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Tan JA, Lao KU. Mapping spin contamination-free potential energy surfaces using restricted open-shell methods with Grassmannians. Phys Chem Chem Phys 2024; 26:1436-1442. [PMID: 38113092 DOI: 10.1039/d3cp05437c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The Lagrange-based Grassmann interpolation (G-Int) method has been extended for open-shell systems using restricted open-shell (RO) methods. The performance of this method was assessed in constructing potential energy surfaces (PESs) for vanadium(II) oxide, benzyl radical, and methanesulfenyl chloride radical cation. The density matrices generated by G-Int when used as initial guesses for self-consistent field (SCF) calculations, exhibit superior performance compared to other traditional SCF initial guess schemes, such as SADMO, GWH, and CORE. Additionally, the energy obtained from the G-Int scheme satisfies the variational principle and outperforms the direct energy-based Lagrange interpolation approach. In the case of methanesulfenyl chloride radical cation, a unique example with a flat PES at the end region along the H-C-S-Cl dihedral angle, the use of an equally-spaced grid sampling leads to significant oscillations near the end of the interval due to the effects of Runge's phenomenon. Introducing an unequally-spaced grid sampling based on a scaled Gauss-Chebyshev quadrature effectively mitigated the Runge's phenomenon, making it suitable for combining with G-Int in constructing PESs for general applications. Thus, G-Int provides an efficient and robust strategy for building spin contamination-free PESs with consistent accuracy.
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Affiliation(s)
- Jake A Tan
- Department of Chemistry, Gottwald Center for the Sciences, University of Richmond, Richmond, VA, USA.
| | - Ka Un Lao
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA, USA.
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2
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Abou Taka A, Corzo HH, Pribram Jones A, Hratchian HP. Good Vibrations: Calculating Excited-State Frequencies Using Ground-State Self-Consistent Field Models. J Chem Theory Comput 2022; 18:7286-7297. [PMID: 36445860 DOI: 10.1021/acs.jctc.2c00672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The use of Δ-self-consistent field (SCF) approaches for studying excited electronic states has received a renewed interest in recent years. In this work, the use of this scheme for calculating excited-state vibrational frequencies is examined. Results from Δ-SCF calculations for a set of representative molecules are compared with those obtained using configuration interaction with single substitutions (CIS) and time-dependent density functional theory (TD-DFT) methods. The use of an approximate spin purification model is also considered for cases where the excited-state SCF solution is spin-contaminated. The results of this work demonstrate that an SCF-based description of an excited-state potential energy surface can be an accurate and cost-effective alternative to CIS and TD-DFT methods.
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Affiliation(s)
- Ali Abou Taka
- Department of Chemistry and Biochemistry and Center for Chemical Computation and Theory, University of California, Merced, California95343, United States.,Combustion Research Facility, Sandia National Laboratories, Livermore, California94550, United States
| | - Hector H Corzo
- Department of Chemistry and Biochemistry and Center for Chemical Computation and Theory, University of California, Merced, California95343, United States.,National Center for Computational Sciences, Oak Ridge Leadership Computing Facility, Oak Ridge National laboratory, Oak Ridge, Tennessee37831-6012, United States
| | - Aurora Pribram Jones
- Department of Chemistry and Biochemistry and Center for Chemical Computation and Theory, University of California, Merced, California95343, United States
| | - Hrant P Hratchian
- Department of Chemistry and Biochemistry and Center for Chemical Computation and Theory, University of California, Merced, California95343, United States
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3
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Abou Taka A, Lu SY, Gowland D, Zuehlsdorff TJ, Corzo HH, Pribram-Jones A, Shi L, Hratchian HP, Isborn CM. Comparison of Linear Response Theory, Projected Initial Maximum Overlap Method, and Molecular Dynamics-Based Vibronic Spectra: The Case of Methylene Blue. J Chem Theory Comput 2022; 18:3039-3051. [PMID: 35472264 DOI: 10.1021/acs.jctc.1c01127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The simulation of optical spectra is essential to molecular characterization and, in many cases, critical for interpreting experimental spectra. The most common method for simulating vibronic absorption spectra relies on the geometry optimization and computation of normal modes for ground and excited electronic states. In this report, we show that the utilization of such a procedure within an adiabatic linear response (LR) theory framework may lead to state mixings and a breakdown of the Born-Oppenheimer approximation, resulting in a poor description of absorption spectra. In contrast, computing excited states via a self-consistent field method in conjunction with a maximum overlap model produces states that are not subject to such mixings. We show that this latter method produces vibronic spectra much more aligned with vertical gradient and molecular dynamics (MD) trajectory-based approaches. For the methylene blue chromophore, we compare vibronic absorption spectra computed with the following: an adiabatic Hessian approach with LR theory-optimized structures and normal modes, a vertical gradient procedure, the Hessian and normal modes of maximum overlap method-optimized structures, and excitation energy time-correlation functions generated from an MD trajectory. Because of mixing between the bright S1 and dark S2 surfaces near the S1 minimum, computing the adiabatic Hessian with LR theory and time-dependent density functional theory with the B3LYP density functional predicts a large vibronic shoulder for the absorption spectrum that is not present for any of the other methods. Spectral densities are analyzed and we compare the behavior of the key normal mode that in LR theory strongly couples to the optical excitation while showing S1/S2 state mixings. Overall, our study provides a note of caution in computing vibronic spectra using the excited-state adiabatic Hessian of LR theory-optimized structures and also showcases three alternatives that are less sensitive to adiabatic state mixing effects.
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Affiliation(s)
- Ali Abou Taka
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Shao-Yu Lu
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Duncan Gowland
- Department of Physics, King's College London, London WC2R 2LS, United Kingdom
| | - Tim J Zuehlsdorff
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Hector H Corzo
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Aurora Pribram-Jones
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Liang Shi
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Hrant P Hratchian
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Christine M Isborn
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
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4
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Baudhuin MA, Boopalachandran P, Rajan S, Leopold DG. A Study of NbMo and NbMo - by Anion Photoelectron Spectroscopy. J Phys Chem A 2021; 125:9658-9679. [PMID: 34723518 DOI: 10.1021/acs.jpca.1c07669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photoelectron spectra of the niobium-molybdenum diatomic anion, obtained at 488 and 514 nm, display vibrationally resolved transitions from the ground state and one excited electronic state of the anion to the ground state and one excited electronic state of the neutral molecule. The electron affinity of NbMo is measured to be 1.130 ± 0.005 eV. Its 2Δ3/2 spin-orbit component is observed to lie 870 ± 20 cm-1 above its previously identified 2Δ5/2 ground state. For 93Nb98Mo, vibrational energies measured for levels up to v = 4 for the 2Δ5/2 and 2Δ3/2 states give harmonic frequency and anharmonicity constant values of ωe = 492 ± 12 cm-1 and ωexe = 8.0 ± 3.2 cm-1, the former value corresponding to a force constant of 6.80 ± 0.35 mdyn/Å. These two vibrational parameters suggest a bond dissociation energy that is too low by at least a factor of 3, indicating that the ground state potential energy curve of NbMo deviates markedly from a Morse potential at higher energies. An excited electronic state of NbMo, assigned as a 2Σ+ state, is observed at 2900 ± 25 cm-1 (T0). Vibrational energies up to v = 8 in this excited state give values of ωe = 544 ± 8 cm-1 and ωexe = 1.9 ± 1.2 cm-1 for 93Nb98Mo. The former value corresponds to a high vibrational force constant of 8.30 ± 0.25 mdyn/Å. Both doublet states of the neutral molecule are accessed from the anion ground state, which is assigned as 1Σ+. For the 93Nb98Mo- anion, the fundamental vibrational frequency (ΔG1/2) is 484 ± 15 cm-1. Electron affinity data indicate that the bond dissociation energy of NbMo- is 0.213 ± 0.005 eV greater than that of neutral NbMo, whose previously reported value then gives D0 = 4.85 ± 0.27 eV for the anion. An excited state of the anion lying 3050 ± 25 cm-1 (T0) above its ground state is assigned as 3Δ, and the energies of its spin-orbit components above the 3Δ3 lowest energy level are measured to be 450 ± 20 cm-1 (3Δ2) and 1100 ± 20 cm-1 (3Δ1). Their uneven spacing suggests that the energy of the 3Δ2 level is lowered by interaction with a higher energy Ω = 2 anion state. The vibrational frequency (ΔG1/2) for the 3Δ1 and 3Δ2 states is measured to be 433 ± 20 cm-1. Bond length differences among the observed states are estimated from Franck-Condon fits to vibrational band intensity profiles. When combined with the previously reported NbMo bond length, these provide bond length estimates for the ground state of the anion (1.940 ± 0.025 Å) and for the observed excited states. These species offer extreme examples of multiple metal-metal bonding, with formal bond orders of 51/2 for the 2Δ ground and 2Σ+ excited doublet states of NbMo, 6 for the singlet ground state of the anion, and 5 for its low-lying triplet state. The relationships among their bonding properties and those of related multiply bonded transition metal dimers are discussed.
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Affiliation(s)
- Melissa A Baudhuin
- Chemistry Department, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota55455, United States
| | - Praveenkumar Boopalachandran
- Chemistry Department, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota55455, United States
| | - Srijay Rajan
- Chemistry Department, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota55455, United States
| | - Doreen Geller Leopold
- Chemistry Department, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, Minnesota55455, United States
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5
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Harb H, Hratchian HP. ΔSCF Dyson orbitals and pole strengths from natural ionization orbitals. J Chem Phys 2021; 154:084104. [DOI: 10.1063/5.0040454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Hassan Harb
- Department of Chemistry and Chemical Biology and Center for Chemical Computation and Theory, University of California, Merced, California 95343, USA
| | - Hrant P. Hratchian
- Department of Chemistry and Chemical Biology and Center for Chemical Computation and Theory, University of California, Merced, California 95343, USA
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6
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Sheng X, Thompson LM, Hratchian HP. Assessing the Calculation of Exchange Coupling Constants and Spin Crossover Gaps Using the Approximate Projection Model To Improve Density Functional Calculations. J Chem Theory Comput 2019; 16:154-163. [PMID: 31743016 DOI: 10.1021/acs.jctc.9b00387] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work evaluates the quality of exchange coupling constant and spin crossover gap calculations using density functional theory corrected by the approximate projection model. Results show that improvements using the approximate projection model range from modest to significant. This study demonstrates that, at least for the class of systems examined here, spin projection generally improves the quality of density functional theory calculations of J-coupling constants and spin crossover gaps. Furthermore, it is shown that spin projection can be important for both geometry optimization and energy evaluations. The approximate projection model provides an affordable and practical approach for effectively correcting spin-contamination errors in such calculations.
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Affiliation(s)
- Xianghai Sheng
- Department of Chemistry and Chemical Biology & Center for Chemical Computation and Theory , University of California , Merced , California 95343 , United States
| | - Lee M Thompson
- Department of Chemistry and Chemical Biology & Center for Chemical Computation and Theory , University of California , Merced , California 95343 , United States.,Department of Chemistry , University of Louisville , Louisville , Kentucky 40292 , United States
| | - Hrant P Hratchian
- Department of Chemistry and Chemical Biology & Center for Chemical Computation and Theory , University of California , Merced , California 95343 , United States
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7
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Lee J, Head-Gordon M. Two single-reference approaches to singlet biradicaloid problems: Complex, restricted orbitals and approximate spin-projection combined with regularized orbital-optimized Møller-Plesset perturbation theory. J Chem Phys 2019; 150:244106. [DOI: 10.1063/1.5097613] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joonho Lee
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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8
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Mason JL, Harb H, Huizenga CD, Ewigleben JC, Topolski JE, Hratchian HP, Jarrold CC. Electronic and Molecular Structures of the CeB6 Monomer. J Phys Chem A 2019; 123:2040-2048. [DOI: 10.1021/acs.jpca.8b12399] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jarrett L. Mason
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Hassan Harb
- Department of Chemistry and Chemical Biology, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Caleb D. Huizenga
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Joshua C. Ewigleben
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Josey E. Topolski
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Hrant P. Hratchian
- Department of Chemistry and Chemical Biology, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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9
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Harb H, Thompson LM, Hratchian HP. On the linear geometry of lanthanide hydroxide (Ln-OH, Ln = La–Lu). Phys Chem Chem Phys 2019; 21:21890-21897. [DOI: 10.1039/c9cp01560d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Density functional theory predicts that lanthanide hydroxides are linear, with the lanthanide-hydroxide bond being characterized as a covalent triple bond.
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Affiliation(s)
- Hassan Harb
- Department of Chemistry & Chemical Biology and the Center for Chemical Computation and Theory
- University of California
- California 95343
- USA
| | - Lee M. Thompson
- Department of Chemistry & Chemical Biology and the Center for Chemical Computation and Theory
- University of California
- California 95343
- USA
| | - Hrant P. Hratchian
- Department of Chemistry & Chemical Biology and the Center for Chemical Computation and Theory
- University of California
- California 95343
- USA
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11
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Thompson LM. Global elucidation of broken symmetry solutions to the independent particle model through a Lie algebraic approach. J Chem Phys 2018; 149:194106. [DOI: 10.1063/1.5049827] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Lee M. Thompson
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40205, USA
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12
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Xu L, Kumar A, Wong BM. Linear polarizabilities and second hyperpolarizabilities of streptocyanines: Results from broken‐Symmetry DFT and new CCSD(T) benchmarks. J Comput Chem 2018; 39:2350-2359. [DOI: 10.1002/jcc.25519] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 05/06/2018] [Accepted: 06/14/2018] [Indexed: 01/29/2023]
Affiliation(s)
- Lihua Xu
- Department of Chemical & Environmental Engineering, Materials Science & Engineering Program and Department of Physics & Astronomy University of California‐Riverside Riverside California 92521
| | - Anshuman Kumar
- Department of Chemical & Environmental Engineering, Materials Science & Engineering Program and Department of Physics & Astronomy University of California‐Riverside Riverside California 92521
| | - Bryan M. Wong
- Department of Chemical & Environmental Engineering, Materials Science & Engineering Program and Department of Physics & Astronomy University of California‐Riverside Riverside California 92521
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13
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Thompson LM, Jarrold CC, Hratchian HP. Explaining the MoVO4− photoelectron spectrum: Rationalization of geometric and electronic structure. J Chem Phys 2017; 146:104301. [DOI: 10.1063/1.4977418] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Lee M. Thompson
- Chemistry and Chemical Biology, University of California, Merced, California 95343, USA
| | - Caroline C. Jarrold
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Hrant P. Hratchian
- Chemistry and Chemical Biology, University of California, Merced, California 95343, USA
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Oviedo MB, Ilawe NV, Wong BM. Polarizabilities of π-Conjugated Chains Revisited: Improved Results from Broken-Symmetry Range-Separated DFT and New CCSD(T) Benchmarks. J Chem Theory Comput 2016; 12:3593-602. [DOI: 10.1021/acs.jctc.6b00360] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Belén Oviedo
- Department of Chemical & Environmental Engineering and Materials Science & Engineering Program, University of California-Riverside, Riverside, California 92521,United States
| | - Niranjan V. Ilawe
- Department of Chemical & Environmental Engineering and Materials Science & Engineering Program, University of California-Riverside, Riverside, California 92521,United States
| | - Bryan M. Wong
- Department of Chemical & Environmental Engineering and Materials Science & Engineering Program, University of California-Riverside, Riverside, California 92521,United States
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15
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Thompson LM, Harb H, Hratchian HP. Natural ionization orbitals for interpreting electron detachment processes. J Chem Phys 2016; 144:204117. [DOI: 10.1063/1.4951738] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Lee M. Thompson
- Chemistry and Chemical Biology, University of California, Merced, California 95343, USA
| | - Hassan Harb
- Chemistry and Chemical Biology, University of California, Merced, California 95343, USA
| | - Hrant P. Hratchian
- Chemistry and Chemical Biology, University of California, Merced, California 95343, USA
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