1
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Hait D, Lahana D, Fajen OJ, Paz ASP, Unzueta PA, Rana B, Lu L, Wang Y, Kjønstad EF, Koch H, Martínez TJ. Prediction of photodynamics of 200 nm excited cyclobutanone with linear response electronic structure and ab initio multiple spawning. J Chem Phys 2024; 160:244101. [PMID: 38912674 DOI: 10.1063/5.0203800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 05/05/2024] [Indexed: 06/25/2024] Open
Abstract
Simulations of photochemical reaction dynamics have been a challenge to the theoretical chemistry community for some time. In an effort to determine the predictive character of current approaches, we predict the results of an upcoming ultrafast diffraction experiment on the photodynamics of cyclobutanone after excitation to the lowest lying Rydberg state (S2). A picosecond of nonadiabatic dynamics is described with ab initio multiple spawning. We use both time dependent density functional theory (TDDFT) and equation-of-motion coupled cluster singles and doubles (EOM-CCSD) theory for the underlying electronic structure theory. We find that the lifetime of the S2 state is more than a picosecond (with both TDDFT and EOM-CCSD). The predicted ultrafast electron diffraction spectrum exhibits numerous structural features, but weak time dependence over the course of the simulations.
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Affiliation(s)
- Diptarka Hait
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - Dean Lahana
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - O Jonathan Fajen
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - Amiel S P Paz
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - Pablo A Unzueta
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - Bhaskar Rana
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - Lixin Lu
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - Yuanheng Wang
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
| | - Eirik F Kjønstad
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
- Department of Chemistry, Norwegian University of Science and Technology, Trondheim 7491, Norway
| | - Henrik Koch
- Department of Chemistry, Norwegian University of Science and Technology, Trondheim 7491, Norway
| | - Todd J Martínez
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, California 94024, USA
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2
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Makhov DV, Hutton L, Kirrander A, Shalashilin DV. Ultrafast electron diffraction of photoexcited gas-phase cyclobutanone predicted by ab initio multiple cloning simulations. J Chem Phys 2024; 160:164310. [PMID: 38661201 DOI: 10.1063/5.0203683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/02/2024] [Indexed: 04/26/2024] Open
Abstract
We present the result of our calculations of ultrafast electron diffraction (UED) for cyclobutanone excited into the S2 electronic state, which is based on the non-adiabatic dynamics simulations with the Ab Initio Multiple Cloning (AIMC) method with the electronic structure calculated at the SA(3)-CASSCF(12,12)/aug-cc-pVDZ level of theory. The key features in the UED pattern were identified, which can be used to distinguish between the reaction pathways observed in the AIMC dynamics, although there is a significant overlap between representative signals due to the structural similarity of the products. The calculated UED pattern can be compared with the experiment.
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Affiliation(s)
- Dmitry V Makhov
- School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
- School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, United Kingdom
| | - Lewis Hutton
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Adam Kirrander
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
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3
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Janoš J, Figueira Nunes JP, Hollas D, Slavíček P, Curchod BFE. Predicting the photodynamics of cyclobutanone triggered by a laser pulse at 200 nm and its MeV-UED signals-A trajectory surface hopping and XMS-CASPT2 perspective. J Chem Phys 2024; 160:144305. [PMID: 38591685 DOI: 10.1063/5.0203105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/14/2024] [Indexed: 04/10/2024] Open
Abstract
This work is part of a prediction challenge that invited theoretical/computational chemists to predict the photochemistry of cyclobutanone in the gas phase, excited at 200 nm by a laser pulse, and the expected signal that will be recorded during a time-resolved megaelectronvolt ultrafast electron diffraction (MeV-UED). We present here our theoretical predictions based on a combination of trajectory surface hopping with XMS-CASPT2 (for the nonadiabatic molecular dynamics) and Born-Oppenheimer molecular dynamics with MP2 (for the athermal ground-state dynamics following internal conversion), coined (NA+BO)MD. The initial conditions were sampled from Born-Oppenheimer molecular dynamics coupled to a quantum thermostat. Our simulations indicate that the main photoproducts after 2 ps of dynamics are CO + cyclopropane (50%), CO + propene (10%), and ethene and ketene (34%). The photoexcited cyclobutanone in its second excited electronic state S2 can follow two pathways for its nonradiative decay: (i) a ring-opening in S2 and a subsequent rapid decay to the ground electronic state, where the photoproducts are formed, or (ii) a transfer through a closed-ring conical intersection to S1, where cyclobutanone ring opens and then funnels to the ground state. Lifetimes for the photoproduct and electronic populations were determined. We calculated a stationary MeV-UED signal [difference pair distribution function-ΔPDF(r)] for each (interpolated) pathway as well as a time-resolved signal [ΔPDF(r,t) and ΔI/I(s,t)] for the full swarm of (NA+BO)MD trajectories. Furthermore, our analysis provides time-independent basis functions that can be used to fit the time-dependent experimental UED signals [both ΔPDF(r,t) and ΔI/I(s,t)] and potentially recover the population of photoproducts. We also offer a detailed analysis of the limitations of our model and their potential impact on the predicted experimental signals.
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Affiliation(s)
- Jiří Janoš
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, Prague 6 166 28, Czech Republic
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | | | - Daniel Hollas
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Petr Slavíček
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, Prague 6 166 28, Czech Republic
| | - Basile F E Curchod
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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4
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Suchan J, Liang F, Durden AS, Levine BG. Prediction challenge: First principles simulation of the ultrafast electron diffraction spectrum of cyclobutanone. J Chem Phys 2024; 160:134310. [PMID: 38573851 DOI: 10.1063/5.0198333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 03/18/2024] [Indexed: 04/06/2024] Open
Abstract
Computer simulation has long been an essential partner of ultrafast experiments, allowing the assignment of microscopic mechanistic detail to low-dimensional spectroscopic data. However, the ability of theory to make a priori predictions of ultrafast experimental results is relatively untested. Herein, as a part of a community challenge, we attempt to predict the signal of an upcoming ultrafast photochemical experiment using state-of-the-art theory in the context of preexisting experimental data. Specifically, we employ ab initio Ehrenfest with collapse to a block mixed quantum-classical simulations to describe the real-time evolution of the electrons and nuclei of cyclobutanone following excitation to the 3s Rydberg state. The gas-phase ultrafast electron diffraction (GUED) signal is simulated for direct comparison to an upcoming experiment at the Stanford Linear Accelerator Laboratory. Following initial ring-opening, dissociation via two distinct channels is observed: the C3 dissociation channel, producing cyclopropane and CO, and the C2 channel, producing CH2CO and C2H4. Direct calculations of the GUED signal indicate how the ring-opened intermediate, the C2 products, and the C3 products can be discriminated in the GUED signal. We also report an a priori analysis of anticipated errors in our predictions: without knowledge of the experimental result, which features of the spectrum do we feel confident we have predicted correctly, and which might we have wrong?
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Affiliation(s)
- Jiří Suchan
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
| | - Fangchun Liang
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
| | - Andrew S Durden
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
| | - Benjamin G Levine
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
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5
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Jiang J, Zhang M, Gu A, Miller RJD, Li Z. Quantum tomography of molecules using ultrafast electron diffraction. J Chem Phys 2024; 160:104101. [PMID: 38456529 DOI: 10.1063/5.0183568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/20/2024] [Indexed: 03/09/2024] Open
Abstract
We propose a quantum tomography (QT) approach to retrieve the temporally evolving reduced density matrix in electronic state basis, where the populations and coherence between the ground state and excited state are reconstructed from the ultrafast electron diffraction signal. In order to showcase the capability of the proposed QT approach, we simulate the nuclear wavepacket dynamics and ultrafast electron diffraction of photoexcited pyrrole molecules using the ab initio quantum chemical CASSCF method. From the simulated time-resolved diffraction data, we retrieve the evolving density matrix in a crude diabatic representation basis and reveal the symmetry of the excited pyrrole wavepacket. Our QT approach opens the route to make a quantum version of "molecular movie" that covers the electronic degree of freedom and equips ultrafast electron diffraction with the power to reveal the coherence between electronic states, relaxation, and dynamics of population transfer.
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Affiliation(s)
- Jiayang Jiang
- Departments of Chemistry and Physics, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Ming Zhang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Aosheng Gu
- Departments of Chemistry and Physics, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - R J Dwayne Miller
- Departments of Chemistry and Physics, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Zheng Li
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
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6
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Figueira Nunes JP, Ibele LM, Pathak S, Attar AR, Bhattacharyya S, Boll R, Borne K, Centurion M, Erk B, Lin MF, Forbes RJG, Goff N, Hansen CS, Hoffmann M, Holland DMP, Ingle RA, Luo D, Muvva SB, Reid AH, Rouzée A, Rudenko A, Saha SK, Shen X, Venkatachalam AS, Wang X, Ware MR, Weathersby SP, Wilkin K, Wolf TJA, Xiong Y, Yang J, Ashfold MNR, Rolles D, Curchod BFE. Monitoring the Evolution of Relative Product Populations at Early Times during a Photochemical Reaction. J Am Chem Soc 2024; 146:4134-4143. [PMID: 38317439 PMCID: PMC10870701 DOI: 10.1021/jacs.3c13046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/10/2024] [Accepted: 01/10/2024] [Indexed: 02/07/2024]
Abstract
Identifying multiple rival reaction products and transient species formed during ultrafast photochemical reactions and determining their time-evolving relative populations are key steps toward understanding and predicting photochemical outcomes. Yet, most contemporary ultrafast studies struggle with clearly identifying and quantifying competing molecular structures/species among the emerging reaction products. Here, we show that mega-electronvolt ultrafast electron diffraction in combination with ab initio molecular dynamics calculations offer a powerful route to determining time-resolved populations of the various isomeric products formed after UV (266 nm) excitation of the five-membered heterocyclic molecule 2(5H)-thiophenone. This strategy provides experimental validation of the predicted high (∼50%) yield of an episulfide isomer containing a strained three-membered ring within ∼1 ps of photoexcitation and highlights the rapidity of interconversion between the rival highly vibrationally excited photoproducts in their ground electronic state.
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Affiliation(s)
| | - Lea Maria Ibele
- CNRS,
Institut de Chimie Physique UMR8000, Université
Paris-Saclay, Orsay, 9140, France
| | - Shashank Pathak
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Andrew R. Attar
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Surjendu Bhattacharyya
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | | | - Kurtis Borne
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Martin Centurion
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Benjamin Erk
- Deutsches
Elektronen Synchrotron DESY, Hamburg, 22607, Germany
| | - Ming-Fu Lin
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Ruaridh J. G. Forbes
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Nathan Goff
- Brown University, Providence, Rhode Island 02912, United States
| | | | - Matthias Hoffmann
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Rebecca A. Ingle
- Department
of Chemistry, University College London, London, WC1H 0AJ, U.K.
| | - Duan Luo
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Sri Bhavya Muvva
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Alexander H. Reid
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Artem Rudenko
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Sajib Kumar Saha
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Xiaozhe Shen
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Anbu Selvam Venkatachalam
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Xijie Wang
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Matt R. Ware
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Kyle Wilkin
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Thomas J. A. Wolf
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
- Stanford
PULSE Institute, SLAC National Accelerator
Laboratory, Menlo
Park, California 94025, United States
| | - Yanwei Xiong
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Jie Yang
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Daniel Rolles
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
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7
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Acheson K, Kirrander A. Robust Inversion of Time-Resolved Data via Forward-Optimization in a Trajectory Basis. J Chem Theory Comput 2023; 19:2721-2734. [PMID: 37129988 DOI: 10.1021/acs.jctc.2c01113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
An inversion method for time-resolved data from ultrafast experiments is introduced, based on forward-optimization in a trajectory basis. The method is applied to experimental data from X-ray scattering of the photochemical ring-opening reaction of 1,3-cyclohexadiene and electron diffraction of the photodissociation of CS2. In each case, inversion yields a model that reproduces the experimental data, identifies the main dynamic motifs, and agrees with independent experimental observations. Notably, the method explicitly accounts for continuity constraints and is robust even for noisy data.
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Affiliation(s)
- Kyle Acheson
- EaStCHEM, School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Adam Kirrander
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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8
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Abstract
Major advances in X-ray sources including the development of circularly polarized and orbital angular momentum pulses make it possible to probe matter chirality at unprecedented energy regimes and with Ångström and femtosecond spatiotemporal resolutions. We survey the theory of stationary and time-resolved nonlinear chiral measurements that can be carried out in the X-ray regime using tabletop X-ray sources or large scale (XFEL, synchrotron) facilities. A variety of possible signals and their information content are discussed.
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Affiliation(s)
- Jérémy R Rouxel
- Université de Lyon, UJM-Saint-Etienne, CNRS, IOGS, Laboratoire Hubert Curien UMR 5516, Saint-Etienne F-42023, France
| | - Shaul Mukamel
- Department of Chemistry and Physics & Astronomy, University of California, Irvine, California 92697-2025, United States
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9
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Yong H, Rouxel JR, Keefer D, Mukamel S. Direct Monitoring of Conical Intersection Passage via Electronic Coherences in Twisted X-Ray Diffraction. PHYSICAL REVIEW LETTERS 2022; 129:103001. [PMID: 36112435 DOI: 10.1103/physrevlett.129.103001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/07/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Quantum coherences in electronic motions play a critical role in determining the pathways and outcomes of virtually all photophysical and photochemical molecular processes. However, the direct observation of electronic coherences in the vicinity of conical intersections remains a formidable challenge. We propose a novel time-resolved twisted x-ray diffraction technique that can directly monitor the electronic coherences created as the molecule passes through a conical intersection. We show that the contribution of electronic populations to this signal is canceled out when using twisted x-ray beams that carry a light orbital angular momentum, providing a direct measurement of transient electronic coherences in gas-phase molecules.
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Affiliation(s)
- Haiwang Yong
- Department of Chemistry, University of California, Irvine, California 92697, USA
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Jérémy R Rouxel
- University Lyon, UJM-Saint-Étienne, CNRS, Graduate School Optics Institute, Laboratoire Hubert Curien UMR 5516, Saint-Étienne 42023, France
| | - Daniel Keefer
- Department of Chemistry, University of California, Irvine, California 92697, USA
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, California 92697, USA
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
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10
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Rouxel JR, Keefer D, Aleotti F, Nenov A, Garavelli M, Mukamel S. Coupled Electronic and Nuclear Motions during Azobenzene Photoisomerization Monitored by Ultrafast Electron Diffraction. J Chem Theory Comput 2022; 18:605-613. [DOI: 10.1021/acs.jctc.1c00792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jérémy R. Rouxel
- Department of Chemistry and Physics & Astronomy, University of California, Irvine, California 92697-2025, United States
- Univ Lyon, UJM-Saint-Etienne, CNRS, Graduate School Optics Institute, Laboratoire Hubert Curien UMR 5516, Saint-Etienne, F-42023, France
| | - Daniel Keefer
- Department of Chemistry and Physics & Astronomy, University of California, Irvine, California 92697-2025, United States
| | - Flavia Aleotti
- Dipartimento di Chimica Industriale, Universitá degli Studi di Bologna, Viale del Risorgimento 4, Bologna, I-40136, Italy
| | - Artur Nenov
- Dipartimento di Chimica Industriale, Universitá degli Studi di Bologna, Viale del Risorgimento 4, Bologna, I-40136, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Universitá degli Studi di Bologna, Viale del Risorgimento 4, Bologna, I-40136, Italy
| | - Shaul Mukamel
- Department of Chemistry and Physics & Astronomy, University of California, Irvine, California 92697-2025, United States
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11
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Moreno Carrascosa A, Coe JP, Simmermacher M, Paterson MJ, Kirrander A. Towards high-resolution X-ray scattering as a probe of electron correlation. Phys Chem Chem Phys 2022; 24:24542-24552. [DOI: 10.1039/d2cp02933b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We demonstrate that X-ray scattering can be used as a probe of electron–electron correlation.
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Affiliation(s)
- Andrés Moreno Carrascosa
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Jeremy P. Coe
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Mats Simmermacher
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Martin J. Paterson
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
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12
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Moreno Carrascosa A, Yang M, Yong H, Ma L, Kirrander A, Weber PM, Lopata K. Mapping static core-holes and ring-currents with X-ray scattering. Faraday Discuss 2021; 228:60-81. [PMID: 33605956 DOI: 10.1039/d0fd00124d] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Measuring the attosecond movement of electrons in molecules is challenging due to the high temporal and spatial resolutions required. X-ray scattering-based methods are promising, but many questions remain concerning the sensitivity of the scattering signals to changes in density, as well as the means of reconstructing the dynamics from these signals. In this paper, we present simulations of stationary core-holes and electron dynamics following inner-shell ionization of the oxazole molecule. Using a combination of time-dependent density functional theory simulations along with X-ray scattering theory, we demonstrate that the sudden core-hole ionization produces a significant change in the X-ray scattering response and how the electron currents across the molecule should manifest as measurable modulations to the time dependent X-ray scattering signal. This suggests that X-ray scattering is a viable probe for measuring electronic processes at time scales faster than nuclear motion.
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Affiliation(s)
| | - Mengqi Yang
- Department of Chemistry, 232 Choppin Hall, Baton Rouge, Louisiana 70803, USA
| | - Haiwang Yong
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lingyu Ma
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, UK
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Kenneth Lopata
- Department of Chemistry, 232 Choppin Hall, Baton Rouge, Louisiana 70803, USA and Center for Computation and Technology, Louisiana State University, Baton Roug, Louisiana 70803, USA.
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13
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Yong H, Xu X, Ruddock JM, Stankus B, Carrascosa AM, Zotev N, Bellshaw D, Du W, Goff N, Chang Y, Boutet S, Carbajo S, Koglin JE, Liang M, Robinson JS, Kirrander A, Minitti MP, Weber PM. Ultrafast X-ray scattering offers a structural view of excited-state charge transfer. Proc Natl Acad Sci U S A 2021; 118:e2021714118. [PMID: 33947814 PMCID: PMC8126834 DOI: 10.1073/pnas.2021714118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intramolecular charge transfer and the associated changes in molecular structure in N,N'-dimethylpiperazine are tracked using femtosecond gas-phase X-ray scattering. The molecules are optically excited to the 3p state at 200 nm. Following rapid relaxation to the 3s state, distinct charge-localized and charge-delocalized species related by charge transfer are observed. The experiment determines the molecular structure of the two species, with the redistribution of electron density accounted for by a scattering correction factor. The initially dominant charge-localized state has a weakened carbon-carbon bond and reorients one methyl group compared with the ground state. Subsequent charge transfer to the charge-delocalized state elongates the carbon-carbon bond further, creating an extended 1.634 Å bond, and also reorients the second methyl group. At the same time, the bond lengths between the nitrogen and the ring-carbon atoms contract from an average of 1.505 to 1.465 Å. The experiment determines the overall charge transfer time constant for approaching the equilibrium between charge-localized and charge-delocalized species to 3.0 ps.
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Affiliation(s)
- Haiwang Yong
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Xuan Xu
- Department of Chemistry, Brown University, Providence, RI 02912
| | | | - Brian Stankus
- Department of Chemistry and Biochemistry, Western Connecticut State University, Danbury, CT 06810
| | | | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Darren Bellshaw
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Wenpeng Du
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Yu Chang
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Sébastien Boutet
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Sergio Carbajo
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Jason E Koglin
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Mengning Liang
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Joseph S Robinson
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom;
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Michael P Minitti
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, RI 02912;
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14
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Imaging conical intersection dynamics during azobenzene photoisomerization by ultrafast X-ray diffraction. Proc Natl Acad Sci U S A 2021; 118:2022037118. [PMID: 33436412 DOI: 10.1073/pnas.2022037118] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
X-ray diffraction is routinely used for structure determination of stationary molecular samples. Modern X-ray photon sources, e.g., from free-electron lasers, enable us to add temporal resolution to these scattering events, thereby providing a movie of atomic motions. We simulate and decipher the various contributions to the X-ray diffraction pattern for the femtosecond isomerization of azobenzene, a textbook photochemical process. A wealth of information is encoded besides real-time monitoring of the molecular charge density for the cis to trans isomerization. In particular, vibronic coherences emerge at the conical intersection, contributing to the total diffraction signal by mixed elastic and inelastic photon scattering. They cause distinct phase modulations in momentum space, which directly reflect the real-space phase modulation of the electronic transition density during the nonadiabatic passage. To overcome the masking by the intense elastic scattering contributions from the electronic populations in the total diffraction signal, we discuss how this information can be retrieved, e.g., by employing very hard X-rays to record large scattering momentum transfers.
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15
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Cavaletto SM, Mukamel S. Probing Delocalized Current Densities in Selenophene by Resonant X-ray Sum-Frequency Generation. J Chem Theory Comput 2021; 17:367-375. [PMID: 33275843 DOI: 10.1021/acs.jctc.0c00886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Time-resolved, resonant X-ray sum-frequency generation in aligned selenophene molecules is calculated. A wave packet of valence-excited states, prepared by an extreme-ultraviolet pump pulse, is probed by two 12-keV X-ray probe pulses resonant with the Se core-excited states for variable time delays. At these hard-X-ray frequencies, the angström wavelength of the X-ray probe is comparable to the molecular size. We thus employ a nonlocal description of the light-matter interaction based on the minimal-coupling Hamiltonian. The wavevector-resolved resonant stimulated sum-frequency-generation signal, obtained by varying the propagation direction of hard-X-ray pulses, can thus directly monitor the transition current densities between core and ground/valence states. This is in contrast to off-resonant diffraction, which detects the transition charge densities.
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Affiliation(s)
- Stefano M Cavaletto
- Department of Chemistry and Department of Physics & Astronomy, University of California, Irvine, California 92697, United States
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics & Astronomy, University of California, Irvine, California 92697, United States
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16
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Rouxel JR, Keefer D, Mukamel S. Signatures of electronic and nuclear coherences in ultrafast molecular x-ray and electron diffraction. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:014101. [PMID: 33457447 PMCID: PMC7803382 DOI: 10.1063/4.0000043] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Femtosecond x-ray and electron diffraction hold promise to image the evolving structures of single molecules. We present a unified quantum-electrodynamical formulation of diffraction signals, based on the exact many-body nuclear + electronic wavefunction that can be extracted from quantum chemistry simulations. This gives a framework for analyzing various approximate molecular dynamics simulations. We show that the complete description of ultrafast diffraction signals contains interesting contributions involving mixed elastic and inelastic scattered photons that are usually masked by other larger contributions and are neglected. These terms include overlaps of nuclear wavepackets between different electronic states that provide an electronic decoherence mechanism and are important for the time-resolved imaging of conical intersections.
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17
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Conti I, Cerullo G, Nenov A, Garavelli M. Ultrafast Spectroscopy of Photoactive Molecular Systems from First Principles: Where We Stand Today and Where We Are Going. J Am Chem Soc 2020; 142:16117-16139. [PMID: 32841559 PMCID: PMC7901644 DOI: 10.1021/jacs.0c04952] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
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Computational spectroscopy is becoming a mandatory tool for the interpretation of the
complex, and often congested, spectral maps delivered by modern non-linear multi-pulse
techniques. The fields of Electronic Structure Methods,
Non-Adiabatic Molecular Dynamics, and Theoretical
Spectroscopy represent the three pillars of the virtual ultrafast
optical spectrometer, able to deliver transient spectra in
silico from first principles. A successful simulation strategy requires a
synergistic approach that balances between the three fields, each one having its very
own challenges and bottlenecks. The aim of this Perspective is to demonstrate that,
despite these challenges, an impressive agreement between theory and experiment is
achievable now regarding the modeling of ultrafast photoinduced processes in complex
molecular architectures. Beyond that, some key recent developments in the three fields
are presented that we believe will have major impacts on spectroscopic simulations in
the very near future. Potential directions of development, pending challenges, and
rising opportunities are illustrated.
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Affiliation(s)
- Irene Conti
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, IFN-CNR, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Artur Nenov
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy
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18
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Observation of the molecular response to light upon photoexcitation. Nat Commun 2020; 11:2157. [PMID: 32358535 PMCID: PMC7195484 DOI: 10.1038/s41467-020-15680-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/23/2020] [Indexed: 12/02/2022] Open
Abstract
When a molecule interacts with light, its electrons can absorb energy from the electromagnetic field by rapidly rearranging their positions. This constitutes the first step of photochemical and photophysical processes that include primary events in human vision and photosynthesis. Here, we report the direct measurement of the initial redistribution of electron density when the molecule 1,3-cyclohexadiene (CHD) is optically excited. Our experiments exploit the intense, ultrashort hard x-ray pulses of the Linac Coherent Light Source (LCLS) to map the change in electron density using ultrafast x-ray scattering. The nature of the excited electronic state is identified with excellent spatial resolution and in good agreement with theoretical predictions. The excited state electron density distributions are thus amenable to direct experimental observation. Photoabsorption is a fundamental process that leads to changes in the electron density in matter. Here, the authors show a direct measurement of the distribution of electron density when a cyclohexadine molecule is excited by pulsed UV radiation and probed by a time delayed X-ray pulse generated at LCLS.
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19
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Zotev N, Moreno Carrascosa A, Simmermacher M, Kirrander A. Excited Electronic States in Total Isotropic Scattering from Molecules. J Chem Theory Comput 2020; 16:2594-2605. [DOI: 10.1021/acs.jctc.9b00670] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikola Zotev
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Andrés Moreno Carrascosa
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Mats Simmermacher
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Adam Kirrander
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
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20
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Hua W, Mukamel S, Luo Y. Transient X-ray Absorption Spectral Fingerprints of the S 1 Dark State in Uracil. J Phys Chem Lett 2019; 10:7172-7178. [PMID: 31625754 DOI: 10.1021/acs.jpclett.9b02692] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Low-lying dark nπ* states play an important role in many photophysical and photochemical processes of organic chromophores. Transient X-ray absorption spectroscopy (TXAS) provides a powerful technique for probing the dynamics of valence states by exciting the electrons into high-lying core excited states. We employ multiconfigurational self-consistent field calculations to investigate the TXAS of uracil along its nonradiative photodecay pathways. An open issue is whether dark nπ* state S1 (n is the lone pair localized on an oxygen atom) is accessible when bright ππ* state S2 is selectively excited. Vertical core excitations were calculated along the potential energy surfaces of the three lowest states, S0-S2, interpolated between two minima and two minimum-energy conical intersections. Computed TXAS data from the C, N, and O K edges show distinct spectral fingerprints of the dark state in all spectral regimes. At the O 1s edge, the nπ* state has a very strong absorption at 526-527 eV, while at the C (N) 1s edge, by contrast, there is almost zero (very weak) absorption at 279-282 eV (397-398 eV). All K-edge spectra can be used to sensitively detect the dark states. Our proposed O 1s feature has already been observed in a recent TXAS experiment with thymine. Natural transition orbital analysis is used to interpret all dominant features of the three lowest-valence states along the reaction coordinate and reveal some important valence fine-structure information from the core excitation.
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Affiliation(s)
- Weijie Hua
- Department of Applied Physics, School of Science , Nanjing University of Science and Technology , 210094 Nanjing , China
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health , KTH Royal Institute of Technology , S-106 91 Stockholm , Sweden
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics and Astronomy , University of California, Irvine , Irvine , California 92697 , United States
| | - Yi Luo
- Hefei National Laboratory for Physical Science at the Microscale , University of Science and Technology of China , 230026 Hefei , China
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21
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Yong H, Ruddock JM, Stankus B, Ma L, Du W, Goff N, Chang Y, Zotev N, Bellshaw D, Boutet S, Carbajo S, Koglin JE, Liang M, Robinson JS, Kirrander A, Minitti MP, Weber PM. Scattering off molecules far from equilibrium. J Chem Phys 2019; 151:084301. [PMID: 31470697 DOI: 10.1063/1.5111979] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Pump-probe gas phase X-ray scattering experiments, enabled by the development of X-ray free electron lasers, have advanced to reveal scattering patterns of molecules far from their equilibrium geometry. While dynamic displacements reflecting the motion of wavepackets can probe deeply into the reaction dynamics, in many systems, the thermal excitation embedded in the molecules upon optical excitation and energy randomization can create systems that encompass structures far from the ground state geometry. For polyatomic molecular systems, large amplitude vibrational motions are associated with anharmonicity and shifts of interatomic distances, making analytical solutions using traditional harmonic approximations inapplicable. More generally, the interatomic distances in a polyatomic molecule are not independent and the traditional equations commonly used to interpret the data may give unphysical results. Here, we introduce a novel method based on molecular dynamic trajectories and illustrate it on two examples of hot, vibrating molecules at thermal equilibrium. When excited at 200 nm, 1,3-cyclohexadiene (CHD) relaxes on a subpicosecond time scale back to the reactant molecule, the dominant pathway, and to various forms of 1,3,5-hexatriene (HT). With internal energies of about 6 eV, the energy thermalizes quickly, leading to structure distributions that deviate significantly from their vibrationless equilibrium. The experimental and theoretical results are in excellent agreement and reveal that a significant contribution to the scattering signal arises from transition state structures near the inversion barrier of CHD. In HT, our analysis clarifies that previous inconsistent structural parameters determined by electron diffraction were artifacts that might have resulted from the use of inapplicable analytical equations.
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Affiliation(s)
- Haiwang Yong
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Jennifer M Ruddock
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Brian Stankus
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lingyu Ma
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Wenpeng Du
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yu Chang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nikola Zotev
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Darren Bellshaw
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Sergio Carbajo
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Jason E Koglin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Mengning Liang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Joseph S Robinson
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Adam Kirrander
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Michael P Minitti
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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22
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Moreno Carrascosa A, Yong H, Crittenden DL, Weber PM, Kirrander A. Ab Initio Calculation of Total X-ray Scattering from Molecules. J Chem Theory Comput 2019; 15:2836-2846. [PMID: 30875212 DOI: 10.1021/acs.jctc.9b00056] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a method to calculate total X-ray scattering cross sections directly from ab initio electronic wave functions in atoms and molecules. The approach can be used in conjunction with multiconfigurational wave functions and exploits analytical integrals of Gaussian-type functions over the scattering operator, which leads to accurate and efficient calculations. The results are validated by comparison to experimental results and previous theory for the molecules H2 and CO2. Importantly, we find that the inelastic component of the total scattering varies strongly with molecular geometry. The method is appropriate for use in conjunction with quantum molecular dynamics simulations for the analysis of new ultrafast X-ray scattering experiments and to interpret accurate gas-phase scattering experiments.
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Affiliation(s)
- Andrés Moreno Carrascosa
- EaStCHEM, School of Chemistry , University of Edinburgh , David Brewster Road , EH9 3FJ Edinburgh , United Kingdom
| | - Haiwang Yong
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Deborah L Crittenden
- Department of Chemistry , University of Canterbury , Private Bag 4800 , Christchurch 8041 , New Zealand
| | - Peter M Weber
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Adam Kirrander
- EaStCHEM, School of Chemistry , University of Edinburgh , David Brewster Road , EH9 3FJ Edinburgh , United Kingdom
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