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Makulski W, Garbacz P. Gas-phase 21 Ne NMR studies and the nuclear magnetic dipole moment of neon-21. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:648-652. [PMID: 32012333 DOI: 10.1002/mrc.5006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 06/10/2023]
Abstract
Gas-phase 21 Ne nuclear magnetic resonance spectra were measured at the natural abundance of 21 Ne isotope for samples consisting of pressurized neon up to 60 bar at room temperature and applying the magnetic field of the strength B0 = 11.7574 T. It showed that the nuclear magnetic resonance frequency is linearly dependent on the density of gaseous neon. The resonance frequency was extrapolated to the zero-density point, and it permitted the determination of the 21 Ne nuclear magnetic moment, μ(21 Ne) = 0.6617774(10) μN . The present value of μ(21 Ne) is not influenced by the bulk magnetic susceptibility of neon and interactions between neon atoms; therefore, it is more precise and reliable than the previous result obtained for μ(21 Ne).
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Affiliation(s)
- Włodzimierz Makulski
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Warszawa, Poland
| | - Piotr Garbacz
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Warszawa, Poland
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2
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Sun S, Li X. Relativistic Effects in Magnetic Circular Dichroism: Restricted Magnetic Balance and Temperature Dependence. J Chem Theory Comput 2020; 16:4533-4542. [DOI: 10.1021/acs.jctc.0c00287] [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)
- Shichao Sun
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Xiaosong Li
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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3
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Martinez-Baez E, Feng R, Pearce CI, Schenter GK, Clark AE. Al27 NMR chemical shift of Al(OH) 4 - calculated from first principles: Assessment of error cancellation in chemically distinct reference and target systems. J Chem Phys 2020; 152:134303. [PMID: 32268758 DOI: 10.1063/1.5144294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Predicting accurate nuclear magnetic resonance chemical shieldings relies upon cancellation of different types of errors between the theoretically calculated shielding constant of the analyte of interest and the reference. Often, the intrinsic error in computed shieldings due to basis sets, approximations in the Hamiltonian, description of the wave function, and dynamic effects is nearly identical between the analyte and reference, yet if the electronic structure or sensitivity to local environment differs dramatically, this cannot be taken for granted. Detailed prior work has examined the octahedral trivalent cation Al(H2O)6 3+, accounting for ab initio intrinsic errors. However, the use of this species as a reference for the chemically distinct tetrahedral anion Al(OH)4 - requires an understanding of how these errors cancel in order to define the limits of accurately predicting Al27 chemical shielding in Al(OH)4 -. In this work, we estimate the absolute shielding of the Al27 nucleus in Al(OH)4 - at the coupled cluster level (515.1 ± 5.3 ppm). Shielding sensitivity to the choice of method approximation and atomic basis sets used has been evaluated. Solvent and thermal effects are assessed through ensemble averaging techniques using ab initio molecular dynamics. The contribution of each type of intrinsic error is assessed for the Al(H2O)6 3+ and Al(OH)4 - ions, revealing significant differences that fundamentally hamper the ability to accurately calculate the Al27 chemical shift of Al(OH)4 - from first principles.
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Affiliation(s)
- Ernesto Martinez-Baez
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
| | - Rulin Feng
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
| | - Carolyn I Pearce
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | | | - Aurora E Clark
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
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4
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Makulski W. (129) Xe and (131) Xe nuclear magnetic dipole moments from gas phase NMR spectra. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:273-279. [PMID: 25594841 DOI: 10.1002/mrc.4191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 10/04/2014] [Accepted: 10/22/2014] [Indexed: 06/04/2023]
Abstract
(3) He, (129) Xe and (131) Xe NMR measurements of resonance frequencies in the magnetic field B0=11.7586 T in different gas phase mixtures have been reported. Precise radiofrequency values were extrapolated to the zero gas pressure limit. These results combined with new quantum chemical values of helium and xenon nuclear magnetic shielding constants were used to determine new accurate nuclear magnetic moments of (129) Xe and (131) Xe in terms of that of the (3) He nucleus. They are as follows: μ((129) Xe) = -0.7779607(158)μN and μ((131) Xe) = +0.6918451(70)μN . By this means, the new 'helium method' for estimations of nuclear dipole moments was successfully tested. Gas phase NMR spectra demonstrate the weak intermolecular interactions observed on the (3) He and (129) Xe and (131) Xe shielding in the gaseous mixtures with Xe, CO2 and SF6 .
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Affiliation(s)
- Włodzimierz Makulski
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
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5
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Makulski W. (83)Kr nuclear magnetic moment in terms of that of (3)He. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:430-434. [PMID: 24842240 DOI: 10.1002/mrc.4083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 03/12/2014] [Accepted: 04/23/2014] [Indexed: 06/03/2023]
Abstract
High resolution NMR spectroscopy was applied to precisely determine the (83)Kr nuclear magnetic dipole moment on the basis of new results available for nuclear magnetic shielding in krypton and helium-3 atoms. Small amounts of (3)He as the solutes and (83)Kr as the buffer gas were observed in (3)He and (83)Kr NMR spectra at the constant external field, B0 = 11.7578 T. In each case, the resonance frequencies (ν(He) and ν(Kr)) were linearly dependent on the density of gaseous solvent. The extrapolation of experimental points to the zero density of gaseous krypton allowed for the evaluation of both resonance frequencies free from intermolecular interactions. By combining these measurements with the recommended (83)Kr chemical shielding value, the nuclear magnetic moment could be determined with much better precision than ever before, μ((83)Kr) = -0.9707297(32)μN, with the improvement due to the greater accuracy of the spectral data.
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Affiliation(s)
- Włodzimierz Makulski
- Laboratory of NMR Spectroscopy, Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warszawa, Poland
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6
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Vaara J, Hanni M, Jokisaari J. Nuclear spin-spin coupling in a van der Waals-bonded system: Xenon dimer. J Chem Phys 2013; 138:104313. [DOI: 10.1063/1.4793745] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kjaer H, Nielsen MR, Pagola GI, Ferraro MB, Lazzeretti P, P. A. Sauer S. Nuclear magnetic resonance J coupling constant polarizabilities of hydrogen peroxide: A basis set and correlation study. J Comput Chem 2012; 33:1845-53. [DOI: 10.1002/jcc.23013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 04/03/2012] [Accepted: 04/19/2012] [Indexed: 11/10/2022]
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9
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Olejniczak M, Bast R, Saue T, Pecul M. A simple scheme for magnetic balance in four-component relativistic Kohn–Sham calculations of nuclear magnetic resonance shielding constants in a Gaussian basis. J Chem Phys 2012; 136:014108. [DOI: 10.1063/1.3671390] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Arcisauskaite V, Knecht S, Sauer SPA, Hemmingsen L. Fully relativistic coupled cluster and DFT study of electric field gradients at Hg in 199Hg compounds. Phys Chem Chem Phys 2012; 14:2651-7. [DOI: 10.1039/c2cp23080a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Cukras J, Sadlej J. Theoretical predictions of the spectroscopic parameters in noble-gas molecules: HXeOH and its complex with water. Phys Chem Chem Phys 2011; 13:15455-67. [PMID: 21804992 DOI: 10.1039/c1cp21359h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We employ state-of-the-art methods and basis sets to study the effect of inserting the Xe atom into the water molecule and the water dimer on their NMR parameters. Our aim is to obtain predictions for the future experimental investigation of novel xenon complexes by NMR spectroscopy. Properties such as molecular structure and energetics have been studied by supermolecular approaches using HF, MP2, CCSD, CCSD(T) and MP4 methods. The bonding in HXeOH···H(2)O complexes has been analyzed by Symmetry-Adapted Perturbation Theory to provide the intricate insight into the nature of the interaction. We focus on vibrational spectra, NMR shielding and spin-spin coupling constants-experimental signals that reflect the electronic structures of the compounds. The parameters have been calculated at electron-correlated and Dirac-Hartree-Fock relativistic levels. This study has elucidated that the insertion of the Xe atom greatly modifies the NMR properties, including both the electron correlation and relativistic effects, the (129)Xe shielding constants decrease in HXeOH and HXeOH···H(2)O in comparison to Xe atom; the (17)O, as a neighbour of Xe, is deshielded too. The HXeOH···H(2)O complex in its most stable form is stabilized mainly by induction and dispersion energies.
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Affiliation(s)
- Janusz Cukras
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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12
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Arcisauskaite V, Melo JI, Hemmingsen L, Sauer SPA. Nuclear magnetic resonance shielding constants and chemical shifts in linear 199Hg compounds: A comparison of three relativistic computational methods. J Chem Phys 2011; 135:044306. [DOI: 10.1063/1.3608153] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Comparison of restricted, unrestricted, inverse, and dual kinetic balances for four-component relativistic calculations. Theor Chem Acc 2011. [DOI: 10.1007/s00214-010-0876-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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14
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Sulzer D, Olejniczak M, Bast R, Saue T. 4-Component relativistic magnetically induced current density using London atomic orbitals. Phys Chem Chem Phys 2011; 13:20682-9. [DOI: 10.1039/c1cp22457c] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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15
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Roukala J, Maldonado AF, Vaara J, Aucar GA, Lantto P. Relativistic effects on group-12 metal nuclear shieldings. Phys Chem Chem Phys 2011; 13:21016-25. [DOI: 10.1039/c1cp22043h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Seino J, Hada M. Magnetic shielding constants calculated by the infinite-order Douglas–Kroll–Hess method with electron-electron relativistic corrections. J Chem Phys 2010; 132:174105. [DOI: 10.1063/1.3413529] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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17
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Yoshizawa T, Hada M. Relativistic and electron-correlation effects on magnetizabilities investigated by the Douglas-Kroll-Hess method and the second-order Møller-Plesset perturbation theory. J Comput Chem 2009; 30:2550-66. [DOI: 10.1002/jcc.21261] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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18
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Iliaš M, Saue T, Enevoldsen T, Jensen HJA. Gauge origin independent calculations of nuclear magnetic shieldings in relativistic four-component theory. J Chem Phys 2009; 131:124119. [DOI: 10.1063/1.3240198] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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19
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Cheng L, Xiao Y, Liu W. Four-component relativistic theory for NMR parameters: Unified formulation and numerical assessment of different approaches. J Chem Phys 2009; 130:144102. [DOI: 10.1063/1.3110602] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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21
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Komorovský S, Repiský M, Malkina OL, Malkin VG, Malkin Ondík I, Kaupp M. A fully relativistic method for calculation of nuclear magnetic shielding tensors with a restricted magnetically balanced basis in the framework of the matrix Dirac–Kohn–Sham equation. J Chem Phys 2008; 128:104101. [DOI: 10.1063/1.2837472] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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22
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Casabianca LB, de Dios AC. Ab initiocalculations of NMR chemical shifts. J Chem Phys 2008; 128:052201. [DOI: 10.1063/1.2816784] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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23
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Straka M, Lantto P, Räsänen M, Vaara J. Theoretical predictions of nuclear magnetic resonance parameters in a novel organo-xenon species: Chemical shifts and nuclear quadrupole couplings in HXeCCH. J Chem Phys 2007; 127:234314. [DOI: 10.1063/1.2805389] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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24
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Hanni M, Lantto P, Iliaš M, Jensen HJA, Vaara J. Relativistic effects in the intermolecular interaction-induced nuclear magnetic resonance parameters of xenon dimer. J Chem Phys 2007; 127:164313. [DOI: 10.1063/1.2777143] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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25
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Vaara J. Theory and computation of nuclear magnetic resonance parameters. Phys Chem Chem Phys 2007; 9:5399-418. [PMID: 17925967 DOI: 10.1039/b706135h] [Citation(s) in RCA: 193] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The art of quantum chemical electronic structure calculation has over the last 15 years reached a point where systematic computational studies of magnetic response properties have become a routine procedure for molecular systems. One of their most prominent areas of application are the spectral parameters of nuclear magnetic resonance (NMR) spectroscopy, due to the immense importance of this experimental method in many scientific disciplines. This article attempts to give an overview on the theory and state-of-the-art of the practical computations in the field, in terms of the size of systems that can be treated, the accuracy that can be expected, and the various factors that would influence the agreement of even the most accurate imaginable electronic structure calculation with experiment. These factors include relativistic effects, thermal effects, as well as solvation/environmental influences, where my group has been active. The dependence of the NMR spectra on external magnetic and optical fields is also briefly touched on.
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Affiliation(s)
- Juha Vaara
- Laboratory of Physical Chemistry, Department of Chemistry, FIN-00014, University of Helsinki, Finland.
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26
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Xiao Y, Peng D, Liu W. Four-component relativistic theory for nuclear magnetic shielding constants: The orbital decomposition approach. J Chem Phys 2007; 126:081101. [PMID: 17343433 DOI: 10.1063/1.2565724] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The authors present a scheme to simplify four-component relativistic calculations of nuclear magnetic shielding constants. The central idea is to decompose each first order orbital into two terms, one is magnetically balanced and directly leads to the diamagnetic term, and the other is, to leading order of relativity, kinetically balanced and can therefore simply be represented in the basis of unperturbed positive energy states. As a matrix formulation, the present approach is far simpler than other operator theories. Combined with the Dirac-Kohn-Sham ansatz, the nuclear magnetic shielding constants for the Kr, Xe, and Rn atoms as well as the HBr and HI molecules are calculated, and the results compare favorably with those of other schemes.
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Affiliation(s)
- Yunlong Xiao
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, and Center for Computational Science and Engineering, Peking University, Beijing 100871, People's Republic of China
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27
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Antusek A, Jaszuński M, Rizzo A. Ab initiostudy of interaction-induced NMR shielding constants in mixed rare gas dimers. J Chem Phys 2007; 126:074303. [PMID: 17328601 DOI: 10.1063/1.2446955] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The interaction-induced contribution to the NMR shielding constants in homonuclear A2 and heteronuclear AB (A,B=He,Ne,Ar) dimers is obtained ab initio by employing a coupled cluster singles and doubles with perturbative treatment of triples wave function model and extended correlation-consistent basis sets. The second virial coefficients entering the expansion of the property with the density are then computed in a fully quantum mechanical approach, for temperatures ranging from the limit of dissociation of the dimer to well above standard conditions. The results can be used to describe the density and temperature dependence of the shielding constants in binary mixtures of helium, neon, and argon. The predicted effects should be observable for the interaction of 21Ne with other rare gases.
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Affiliation(s)
- Andrej Antusek
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01224 Warsaw, Poland
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28
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Ilias M, Saue T. An infinite-order two-component relativistic Hamiltonian by a simple one-step transformation. J Chem Phys 2007; 126:064102. [PMID: 17313208 DOI: 10.1063/1.2436882] [Citation(s) in RCA: 379] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The authors report the implementation of a simple one-step method for obtaining an infinite-order two-component (IOTC) relativistic Hamiltonian using matrix algebra. They apply the IOTC Hamiltonian to calculations of excitation and ionization energies as well as electric and magnetic properties of the radon atom. The results are compared to corresponding calculations using identical basis sets and based on the four-component Dirac-Coulomb Hamiltonian as well as Douglas-Kroll-Hess and zeroth-order regular approximation Hamiltonians, all implemented in the DIRAC program package, thus allowing a comprehensive comparison of relativistic Hamiltonians within the finite basis approximation.
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Affiliation(s)
- Miroslav Ilias
- Laboratoire de Chimie Quantique, Institut de Chimie de Strasbourg, LC3-UMR7177 CNRS/Université Louis Pasteur, 4 Rue Blaise Pascal, F-67000 Strasbourg, France.
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29
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Lantto P, Romero RH, Gómez SS, Aucar GA, Vaara J. Relativistic heavy-atom effects on heavy-atom nuclear shieldings. J Chem Phys 2006; 125:184113. [PMID: 17115744 DOI: 10.1063/1.2378737] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The principal relativistic heavy-atom effects on the nuclear magnetic resonance (NMR) shielding tensor of the heavy atom itself (HAHA effects) are calculated using ab initio methods at the level of the Breit-Pauli Hamiltonian. This is the first systematic study of the main HAHA effects on nuclear shielding and chemical shift by perturbational relativistic approach. The dependence of the HAHA effects on the chemical environment of the heavy atom is investigated for the closed-shell X(2+), X(4+), XH(2), and XH(3) (-) (X=Si-Pb) as well as X(3+), XH(3), and XF(3) (X=P-Bi) systems. Fully relativistic Dirac-Hartree-Fock calculations are carried out for comparison. It is necessary in the Breit-Pauli approach to include the second-order magnetic-field-dependent spin-orbit (SO) shielding contribution as it is the larger SO term in XH(3) (-), XH(3), and XF(3), and is equally large in XH(2) as the conventional, third-order field-independent spin-orbit contribution. Considering the chemical shift, the third-order SO mechanism contributes two-thirds of the difference of approximately 1500 ppm between BiH(3) and BiF(3). The second-order SO mechanism and the numerically largest relativistic effect, which arises from the cross-term contribution of the Fermi contact hyperfine interaction and the relativistically modified spin-Zeeman interaction (FC/SZ-KE), are isotropic and practically independent of electron correlation effects as well as the chemical environment of the heavy atom. The third-order SO terms depend on these factors and contribute both to heavy-atom shielding anisotropy and NMR chemical shifts. While a qualitative picture of heavy-atom chemical shifts is already obtained at the nonrelativistic level of theory, reliable shifts may be expected after including the third-order SO contributions only, especially when calculations are carried out at correlated level. The FC/SZ-KE contribution to shielding is almost completely produced in the s orbitals of the heavy atom, with values diminishing with the principal quantum number. The relative contributions converge to universal fractions for the core and subvalence ns shells. The valence shell contribution is negligible, which explains the HAHA characteristics of the FC/SZ-KE term. Although the nonrelativistic theory gives correct chemical shift trends in present systems, the third-order SO-I terms are necessary for more reliable predictions. All of the presently considered relativistic corrections provide significant HAHA contributions to absolute shielding in heavy atoms.
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Affiliation(s)
- Perttu Lantto
- NMR Research Group, Department of Physical Sciences, University of Oulu, P.O. Box 3000, FIN-90014 Oulu, Finland.
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Bast R, Schwerdtfeger P, Saue T. Parity nonconservation contribution to the nuclear magnetic resonance shielding constants of chiral molecules: A four-component relativistic study. J Chem Phys 2006; 125:64504. [PMID: 16942295 DOI: 10.1063/1.2218333] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A systematic four-component relativistic study of the parity nonconservation (PNC) contribution to the (isotropic) NMR shielding constants of chiral molecules is presented for the P enantiomers of the series H(2)X(2) (X=(17)O,(33)S,(77)Se,(125)Te,(209)Po). The PNC contributions are obtained within a linear response approach at the Hartree-Fock level. A careful design of the basis sets is necessary. The four-component relativistic results based on the Dirac-Coulomb Hamiltonian are compared with the nonrelativistic Levy-Leblond results and those obtained by the spin-free modified Dirac Hamiltonian. The calculations confirm the nonrelativistic scaling law Z(2.4) of the PNC contribution with respect to nuclear charge Z. However, the calculations also show that the overall scaling is significantly modified by relativistic effects. The scalar relativistic effect scales as Z(4.7) for the selected set of molecules, whereas the spin-orbit effect, of opposite sign, scales better than Z(6) and completely dominates the PNC contribution for the heaviest elements. This opens up the intriguing possibility of the experimental observation of PNC effects on NMR parameters of molecules containing heavy atoms. The presented formalism is expected to be valuable in assisting the search for suitable candidate molecules.
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Affiliation(s)
- Radovan Bast
- Laboratoire de Chimie Quantique, Institut de Chimie de Strasbourg, LC3-UMR 7177 CNRS/Université Louis Pasteur, 4 Rue Blaise Pascal, F-67000 Strasbourg, France
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31
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Kudo K, Maeda H, Kawakubo T, Ootani Y, Funaki M, Fukui H. Relativistic calculation of nuclear magnetic shielding using normalized elimination of the small component. J Chem Phys 2006; 124:224106. [PMID: 16784262 DOI: 10.1063/1.2204606] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The normalized elimination of the small component (NESC) theory, recently proposed by Filatov and Cremer, is extended to include magnetic interactions and applied to the calculation of the nuclear magnetic shielding in HX (X=F, Cl, Br, I) systems. The NESC calculations are performed at the levels of the zeroth-order regular approximation (ZORA) and the second-order regular approximation (SORA). The calculations show that the NESC-ZORA results are very close to the NESC-SORA results, except for the shielding of the I nucleus. Both the NESC-ZORA and NESC-SORA calculations yield very similar results to the previously reported values obtained using the relativistic infinite-order two-component coupled Hartree-Fock method. The difference between NESC-ZORA and NESC-SORA results is significant for the shieldings of iodine.
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Affiliation(s)
- K Kudo
- Kitami Institute of Technology, 165 Koencho, Kitami 090-8507, Japan
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Fry JL, Matthews J, Lane JR, Roehl CM, Sinha A, Kjaergaard HG, Wennberg PO. OH-Stretch Vibrational Spectroscopy of Hydroxymethyl Hydroperoxide. J Phys Chem A 2006; 110:7072-9. [PMID: 16737255 DOI: 10.1021/jp0612127] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report measurement and analysis of the photodissociation spectrum of hydroxymethyl hydroperoxide (HOCH(2)OOH) and its partially deuterated analogue, HOCD(2)OOH, in the OH-stretching region. Spectra are obtained by Fourier transform infrared spectroscopy in the 1nu(OH) and 2nu(OH) regions, and by laser induced fluorescence detection of the OH fragment produced from dissociation of HOCH(2)OOH initiated by excitation of the 4nu(OH) and 5nu(OH) overtone regions (action spectroscopy). A one-dimensional local-mode model of each OH chromophore is used with ab initio calculated OH-stretching potential energy and dipole moment curves at the coupled-cluster level of theory. Major features in the observed absorption and photodissociation spectra are explained by our local-mode model. In the 4nu(OH) region, explanation of the photodissocation spectrum requires a nonuniform quantum yield, which is estimated by assuming statistical energy distribution in the excited state. Based on the estimated dissociation threshold, overtone photodissociation is not expected to significantly influence the atmospheric lifetime of hydroxymethyl hydroperoxide.
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Affiliation(s)
- Juliane L Fry
- Arthur Amos Laboratory of Chemical Physics, California Institute of Technology, Pasadena, 91125, USA
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Vukovic L, Jameson CJ, Sears DN. Intermolecular hyperfine tensor for Xe@O2. Density and temperature dependence of Xe chemical shifts in oxygen gas. Mol Phys 2006. [DOI: 10.1080/00268970500525614] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kudo K, Ootani Y, Funaki M, Fukui H. Relativistic calculation of nuclear magnetic shieldings of xenon difluoride. J Chem Phys 2006; 124:116101. [PMID: 16555919 DOI: 10.1063/1.2173999] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- K Kudo
- Kitami Institute of Technology, 165 Koencho, Kitami 090-8507, Japan
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Kudo K, Fukui H. Calculation of nuclear magnetic shieldings using an analytically differentiated relativistic shielding formula. J Chem Phys 2005; 123:114102. [PMID: 16392546 DOI: 10.1063/1.2032408] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Two expressions for nuclear-magnetic-shielding tensor components based on analytically differentiating the electronic energy of a system are presented. The first is based on a second-order Douglas-Kroll-Hess approach, in which the off-diagonal block terms of the transformed Dirac Hamiltonian are diminished to second order with respect to both the electrostatic nuclear attraction potential V and the magnetic vector potential A. The second expression is based on the method of Barysz-Sadlej-Snijders, in which the off-diagonal block terms in the transformed Dirac Hamiltonian are completely eliminated with respect to purely V terms, while they are diminished to second order with respect to terms including A. The two approaches are applied to the calculation of nuclear magnetic shieldings of HX (X=F, Cl, Br, I), H2X (X=O, S, Se, Te), and noble gas X (X =He,Ne,Ar,Kr,Xe) systems with common gauge origins. The results show that relativistic corrections of higher than second order are negligibly small, except for the paramagnetic parts of I, Te, and Xe shieldings. The present calculations yield very large positive values for the anisotropy of proton shielding, deltasigma(H) = sigmaparallel(H)-sigmaperpendicular(H), of HI compared to previous reports. Unfortunately, no experimental values for the anisotropy of proton shielding in HI are available for verification.
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Affiliation(s)
- K Kudo
- Kitami Institute of Technology, Japan
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Soncini A, Fowler P, Zerbetto F. Electric-field perturbations of ring currents in π systems. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Saue T. Spin-Interactions and the Non-relativistic Limit of Electrodynamics. ADVANCES IN QUANTUM CHEMISTRY 2005. [DOI: 10.1016/s0065-3276(05)48020-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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