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Kähler S, Cebreiro-Gallardo A, Pokhilko P, Casanova D, Krylov AI. State-Interaction Approach for Evaluating g-Tensors within EOM-CC and RAS-CI Frameworks: Theory and Benchmarks. J Phys Chem A 2023; 127:8459-8472. [PMID: 37774315 DOI: 10.1021/acs.jpca.3c04134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
Among various techniques designed for studying open-shell species, electron paramagnetic resonance (EPR) spectroscopy plays an important role. The key quantity measured by EPR is the g-tensor, describing the coupling between an external magnetic field and molecular electronic spin. One theoretical framework for quantum chemistry calculations of g-tensors is based on response theory, which involves substantial developments that are specific to the underlying electronic structure models. A simplified and easier-to-implement approach is based on the state-interaction scheme, in which perturbation is included by considering a small number of states. We describe and benchmark the state-interaction approach using equation-of-motion coupled-cluster and restricted-active-space configuration interaction wave functions. The analysis confirms that this approach can deliver accurate results and highlights caveats of applying it, such as a choice of the reference state, convergence with respect to the number of states used in calculations, etc. The analysis also contributes toward a better understanding of challenges in calculations of higher-order properties using approximate wave functions.
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Affiliation(s)
- Sven Kähler
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | | | - Pavel Pokhilko
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - David Casanova
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Euskadi, Spain
| | - Anna I Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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2
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Nyvang A, Olsen J. A relativistic configuration interaction method with general expansions and initial applications to electronic g-factors. J Chem Phys 2023; 159:044102. [PMID: 37486047 DOI: 10.1063/5.0152655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/28/2023] [Indexed: 07/25/2023] Open
Abstract
A new implementation of the orbital-based two-component relativistic configuration interaction approach is reported and applied to calculations of the electronic g-shifts of three diatomic radicals: AlO, HgF, and PdH. The new implementation augments efficient routines for the calculation of nonrelativistic Hamiltonians with new vectorized routines for the calculation of the action of the one-electron spin-orbit operator and allows efficient calculations for the expansion of generalized active space type. The program makes full use of double group as well as time-reversal symmetry. Particle-hole reorganization of the operators is used to improve the efficiency for expansions with nearly fully occupied orbital spaces. The flexibility of the algorithm and program is used to investigate the convergence of electronic g-shifts for the three diatomic radicals as functions of the active space, states included in the orbital optimization, and excitation levels. It was possible to converge to the valence limits within a few percent using expansions containing up to quadruple excitations. However, when excitations from the core orbitals were added, it was not possible to demonstrate convergence to within a few percent with expansions containing at most 10 × 109 determinants.
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Affiliation(s)
- Andreas Nyvang
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK 8000 Aarhus C, Denmark
| | - Jeppe Olsen
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK 8000 Aarhus C, Denmark
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3
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Tran VA, Neese F. Double-hybrid density functional theory for g-tensor calculations using gauge including atomic orbitals. J Chem Phys 2020; 153:054105. [DOI: 10.1063/5.0013799] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- V. A. Tran
- Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany
| | - F. Neese
- Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany
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4
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Zuniga-Gutierrez B, Medel-Juarez V, Varona A, González Ramírez HN, Flores-Moreno R. Calculation of the EPR g-tensor from auxiliary density functional theory. J Chem Phys 2020; 152:014105. [DOI: 10.1063/1.5130174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Bernardo Zuniga-Gutierrez
- Departamento de Química, Universidad de Guadalajara, CUCEI, Blvd. Marcelino García Barragán 1421, C. P. 44430 Guadalajara, Jalisco, Mexico
| | - Victor Medel-Juarez
- Departamento de Química, Universidad de Guadalajara, CUCEI, Blvd. Marcelino García Barragán 1421, C. P. 44430 Guadalajara, Jalisco, Mexico
| | - Andres Varona
- Departamento de Electrónica, Universidad de Guadalajara, CUCEI, Blvd. Marcelino García Barragán 1421, C. P. 44430 Guadalajara, Jalisco, Mexico
| | - Henry Nicole González Ramírez
- Departamento de Química, Universidad de Guadalajara, CUCEI, Blvd. Marcelino García Barragán 1421, C. P. 44430 Guadalajara, Jalisco, Mexico
| | - Roberto Flores-Moreno
- Departamento de Química, Universidad de Guadalajara, CUCEI, Blvd. Marcelino García Barragán 1421, C. P. 44430 Guadalajara, Jalisco, Mexico
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Glasbrenner M, Vogler S, Ochsenfeld C. Linear and sublinear scaling computation of the electronic g-tensor at the density functional theory level. J Chem Phys 2019; 150:024104. [DOI: 10.1063/1.5066266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael Glasbrenner
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
| | - Sigurd Vogler
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
| | - Christian Ochsenfeld
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
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6
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Singh SK, Atanasov M, Neese F. Challenges in Multireference Perturbation Theory for the Calculations of the g-Tensor of First-Row Transition-Metal Complexes. J Chem Theory Comput 2018; 14:4662-4677. [DOI: 10.1021/acs.jctc.8b00513] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saurabh Kumar Singh
- Department of Molecular Theory and Spectroscopy, Max-Planck Institute for Kohlenforschung, Kaiser Wilhelm-Platz-1, Mülheim an der Ruhr, Germany
| | - Mihail Atanasov
- Department of Molecular Theory and Spectroscopy, Max-Planck Institute for Kohlenforschung, Kaiser Wilhelm-Platz-1, Mülheim an der Ruhr, Germany
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Akad. Georgi Bontchev Street 11, 1113 Sofia, Bulgaria
| | - Frank Neese
- Department of Molecular Theory and Spectroscopy, Max-Planck Institute for Kohlenforschung, Kaiser Wilhelm-Platz-1, Mülheim an der Ruhr, Germany
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Glasbrenner M, Vogler S, Ochsenfeld C. Gauge-origin dependence in electronic g-tensor calculations. J Chem Phys 2018; 148:214101. [DOI: 10.1063/1.5028454] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael Glasbrenner
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
| | - Sigurd Vogler
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
| | - Christian Ochsenfeld
- Chair of Theoretical Chemistry and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, University of Munich (LMU), Butenandtstr. 7, 81377 Munich, Germany
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8
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Yi J, Chen F. Application of multireference linearized coupled-cluster theory to atomic and molecular systems. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2018. [DOI: 10.1142/s0219633618500165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Applications of the multireference linearized coupled-cluster single-doubles (MRLCCSD) to atomic and molecular systems have been carried out. MRLCCSD is exploited to calculate the ground-state energies of HF, H2O, NH3, CH4, N2, BF, and C2with basis sets, cc-pVDZ, cc-pVTZ and cc-pVQZ. The equilibrium bond lengths and vibration frequencies of HF, HCl, Li2, LiH, LiF, LiBr, BH, and AlF are computed with MRLCCSD and compared with the experimental data. The electron affinities of F and CH as well as the proton affinities of H2O and NH3are also calculated with MRLCCSD. These results are compared with the results produced with second-order perturbation theory, linearized coupled-cluster doubles (LCCD), coupled-cluster doubles (CCD), coupled-cluster singles and doubles (CCSD), CCSD with perturbative triples correction (CCSD(T)). It is shown that all results obtained with MRLCCSD are reliable and accurate.
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Affiliation(s)
- Jiang Yi
- Department of Chemistry and Chemical Engineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China
| | - Feiwu Chen
- Beijing Key Laboratory for Science and Application of Functional, Molecular and Crystalline Materials, Beijing 100083, P. R. China
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Perera A, Gauss J, Verma P, Morales JA. Benchmark coupled-cluster g-tensor calculations with full inclusion of the two-particle spin-orbit contributions. J Chem Phys 2017; 146:164104. [PMID: 28456206 DOI: 10.1063/1.4979680] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We present a parallel implementation to compute electron spin resonance g-tensors at the coupled-cluster singles and doubles (CCSD) level which employs the ACES III domain-specific software tools for scalable parallel programming, i.e., the super instruction architecture language and processor (SIAL and SIP), respectively. A unique feature of the present implementation is the exact (not approximated) inclusion of the five one- and two-particle contributions to the g-tensor [i.e., the mass correction, one- and two-particle paramagnetic spin-orbit, and one- and two-particle diamagnetic spin-orbit terms]. Like in a previous implementation with effective one-electron operators [J. Gauss et al., J. Phys. Chem. A 113, 11541-11549 (2009)], our implementation utilizes analytic CC second derivatives and, therefore, classifies as a true CC linear-response treatment. Therefore, our implementation can unambiguously appraise the accuracy of less costly effective one-particle schemes and provide a rationale for their widespread use. We have considered a large selection of radicals used previously for benchmarking purposes including those studied in earlier work and conclude that at the CCSD level, the effective one-particle scheme satisfactorily captures the two-particle effects less costly than the rigorous two-particle scheme. With respect to the performance of density functional theory (DFT), we note that results obtained with the B3LYP functional exhibit the best agreement with our CCSD results. However, in general, the CCSD results agree better with the experimental data than the best DFT/B3LYP results, although in most cases within the rather large experimental error bars.
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Affiliation(s)
- Ajith Perera
- Department of Chemistry and Biochemistry, Texas Tech University, P.O. Box 41061, Lubbock, Texas 79409-1061, USA
| | - Jürgen Gauss
- Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany
| | - Prakash Verma
- Department of Chemistry and Biochemistry, Texas Tech University, P.O. Box 41061, Lubbock, Texas 79409-1061, USA
| | - Jorge A Morales
- Department of Chemistry and Biochemistry, Texas Tech University, P.O. Box 41061, Lubbock, Texas 79409-1061, USA
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10
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Dutta S, Deka RC. Zero field splitting in Mn (III) complexes: A comparative study of DFT base Coupled-Perturbed and Pederson–Khanna approaches. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.08.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Schmidt TC, Paasche A, Grebner C, Ansorg K, Becker J, Lee W, Engels B. QM/MM investigations of organic chemistry oriented questions. Top Curr Chem (Cham) 2014; 351:25-101. [PMID: 22392477 DOI: 10.1007/128_2011_309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
About 35 years after its first suggestion, QM/MM became the standard theoretical approach to investigate enzymatic structures and processes. The success is due to the ability of QM/MM to provide an accurate atomistic picture of enzymes and related processes. This picture can even be turned into a movie if nuclei-dynamics is taken into account to describe enzymatic processes. In the field of organic chemistry, QM/MM methods are used to a much lesser extent although almost all relevant processes happen in condensed matter or are influenced by complicated interactions between substrate and catalyst. There is less importance for theoretical organic chemistry since the influence of nonpolar solvents is rather weak and the effect of polar solvents can often be accurately described by continuum approaches. Catalytic processes (homogeneous and heterogeneous) can often be reduced to truncated model systems, which are so small that pure quantum-mechanical approaches can be employed. However, since QM/MM becomes more and more efficient due to the success in software and hardware developments, it is more and more used in theoretical organic chemistry to study effects which result from the molecular nature of the environment. It is shown by many examples discussed in this review that the influence can be tremendous, even for nonpolar reactions. The importance of environmental effects in theoretical spectroscopy was already known. Due to its benefits, QM/MM can be expected to experience ongoing growth for the next decade.In the present chapter we give an overview of QM/MM developments and their importance in theoretical organic chemistry, and review applications which give impressions of the possibilities and the importance of the relevant effects. Since there is already a bunch of excellent reviews dealing with QM/MM, we will discuss fundamental ingredients and developments of QM/MM very briefly with a focus on very recent progress. For the applications we follow a similar strategy.
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Affiliation(s)
- Thomas C Schmidt
- Institut für Phys. und Theor. Chemie, Emil-Fischer-Strasse 42, Campus Hubland Nord, 97074, Würzburg, Germany
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12
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Tanaka K, Harada K, Oka T. Ortho–Para Mixing Hyperfine Interaction in the H2O+ Ion and Nuclear Spin Equilibration. J Phys Chem A 2013; 117:9584-92. [DOI: 10.1021/jp312270u] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Keiichi Tanaka
- Department of Applied Chemistry, National Chiao Tung University, 1001 Ta-Hsueh Rd.,
Hsinchu 30010, Taiwan
- Department
of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan
| | - Kensuke Harada
- Department
of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan
| | - Takeshi Oka
- Department of Astronomy and Astrophysics and
Department of Chemistry, the Enrico Fermi Institute, the University of Chicago, Chicago, Illinois 60637,
United States
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13
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Verma P, Autschbach J. Variational versus Perturbational Treatment of Spin–Orbit Coupling in Relativistic Density Functional Calculations of Electronic g Factors: Effects from Spin-Polarization and Exact Exchange. J Chem Theory Comput 2013; 9:1052-67. [DOI: 10.1021/ct3009864] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Prakash Verma
- Department of Chemistry, State University of New York
at Buffalo, Buffalo, New York 14260-3000
| | - Jochen Autschbach
- Department of Chemistry, State University of New York
at Buffalo, Buffalo, New York 14260-3000
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14
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Helgaker T, Coriani S, Jørgensen P, Kristensen K, Olsen J, Ruud K. Recent Advances in Wave Function-Based Methods of Molecular-Property Calculations. Chem Rev 2012; 112:543-631. [DOI: 10.1021/cr2002239] [Citation(s) in RCA: 463] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Trygve Helgaker
- Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway
| | - Sonia Coriani
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via Giorgieri 1, I-34127 Trieste, Italy
| | - Poul Jørgensen
- Lundbeck Center for Theoretical Chemistry, Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
| | - Kasper Kristensen
- Lundbeck Center for Theoretical Chemistry, Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
| | - Jeppe Olsen
- Lundbeck Center for Theoretical Chemistry, Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
| | - Kenneth Ruud
- Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
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Rokob TA, Srnec M, Rulíšek L. Theoretical calculations of physico-chemical and spectroscopic properties of bioinorganic systems: current limits and perspectives. Dalton Trans 2012; 41:5754-68. [DOI: 10.1039/c2dt12423h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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16
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Perumal SS. Zero-field splitting of compact trimethylenemethane analogue radicals with density functional theory. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2010.11.068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Sayin U, Dereli Ö, Türkkan E, Yüksel H, Birey M. EPR study of gamma irradiated 2,5-di-tert-butyl-hydroquinone single crystals. Radiat Phys Chem Oxf Engl 1993 2011. [DOI: 10.1016/j.radphyschem.2010.08.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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18
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Kadantsev ES, Ziegler T. First-principles calculation of parameters of electron paramagnetic resonance spectroscopy in solids. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2010; 48 Suppl 1:S2-S10. [PMID: 20821407 DOI: 10.1002/mrc.2655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The hyperfine A-tensor and Zeeman g-tensor parameterize the interaction of an 'effective' electron spin with the magnetic field due to the nuclear spin and the homogeneous external magnetic field, respectively. The A- and g-tensors are the quantities of primary interest in electron paramagnetic resonance (EPR) spectroscopy. In this paper, we review our work [E.S. Kadantsev, T. Ziegler, J. Phys. Chem. A 2008, 112, 4521; E. S. Kadantsev, T. Ziegler, J. Phys. Chem. A 2009, 113, 1327] on the calculation of these EPR parameters under periodic boundary conditions (PBC) from first-principles. Our methodology is based on the Kohn-Sham DFT (KS DFT), explicit usage of Bloch basis set made up of numerical and Slater-type atomic orbitals (NAOs/STOs), and is implemented in the 'full potential' program BAND. Our implementation does not rely on the frozen core approximation. The NAOs/STOs basis is well suited for the accurate representation of the electron density near the nuclei, a prerequisite for the calculation of highly accurate hyperfine parameters. In the case of g-tensor, our implementation is based on the method of Van Lenthe et al. [E. van Lenthe, P. E. S. Wormer, A. van der Avoird, J. Chem. Phys. 1997, 107, 2488] in which the spin-orbital coupling is taken into account variationally. We demonstrate the viability of our scheme by calculating EPR parameters of paramagnetic defects in solids. We consider the A-tensor of 'normal' and 'anomalous' muonium defect in IIIA-VA semiconductors as well as the S2 anion radical in KCl host crystal lattice.
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Affiliation(s)
- Eugene S Kadantsev
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
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19
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Neese F. Analytic derivative calculation of electronicg-tensors based on multireference configuration interaction wavefunctions. Mol Phys 2010. [DOI: 10.1080/00268970701549389] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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20
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Vancoillie S, Chalupský J, Ryde U, Solomon EI, Pierloot K, Neese F, Rulísek L. Multireference ab initio calculations of g tensors for trinuclear copper clusters in multicopper oxidases. J Phys Chem B 2010; 114:7692-702. [PMID: 20469875 DOI: 10.1021/jp103098r] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
EPR spectroscopy has proven to be an indispensable tool in elucidating the structure of metal sites in proteins. In recent years, experimental EPR data have been complemented by theoretical calculations, which have become a standard tool of many quantum chemical packages. However, there have only been a few attempts to calculate EPR g tensors for exchange-coupled systems with more than two spins. In this work, we present a quantum chemical study of structural, electronic, and magnetic properties of intermediates in the reaction cycle of multicopper oxidases and of their inorganic models. All these systems contain three copper(II) ions bridged by hydroxide or O(2-) anions and their ground states are antiferromagnetically coupled doublets. We demonstrate that only multireference methods, such as CASSCF/CASPT2 or MRCI can yield qualitatively correct results (compared to the experimental values) and consider the accuracy of the calculated EPR g tensors as the current benchmark of quantum chemical methods. By decomposing the calculated g tensors into terms arising from interactions of the ground state with the various excited states, the origin of the zero-field splitting is explained. The results of the study demonstrate that a truly quantitative prediction of the g tensors of exchange-coupled systems is a great challenge to contemporary theory. The predictions strongly depend on small energy differences that are difficult to predict with sufficient accuracy by any quantum chemical method that is applicable to systems of the size of our target systems.
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Affiliation(s)
- Steven Vancoillie
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee-Leuven, Belgium
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21
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Tarczay G, Szalay PG, Gauss J. First-Principles Calculation of Electron Spin-Rotation Tensors. J Phys Chem A 2010; 114:9246-52. [DOI: 10.1021/jp103789x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- György Tarczay
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518, Budapest 112, Hungary, Laboratory of Theoretical Chemistry, Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518, Budapest 112, Hungary, and Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany
| | - Péter G. Szalay
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518, Budapest 112, Hungary, Laboratory of Theoretical Chemistry, Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518, Budapest 112, Hungary, and Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany
| | - Jürgen Gauss
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518, Budapest 112, Hungary, Laboratory of Theoretical Chemistry, Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518, Budapest 112, Hungary, and Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany
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22
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Sayin U, Türkkan E, Dereli Ö, Yüksel H, Birey M. EPR study of gamma-irradiated single crystal 4-phenylsemicarbazide. Radiat Phys Chem Oxf Engl 1993 2010. [DOI: 10.1016/j.radphyschem.2010.03.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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23
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Gauss J, Kállay M, Neese F. Calculation of Electronic g-Tensors using Coupled Cluster Theory. J Phys Chem A 2009; 113:11541-9. [DOI: 10.1021/jp9028535] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Jürgen Gauss
- Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, P.O. Box 91, H-1521 Budapest, Hungary, and Institut für Physikalische und Theoretische Chemie, Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
| | - Mihály Kállay
- Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, P.O. Box 91, H-1521 Budapest, Hungary, and Institut für Physikalische und Theoretische Chemie, Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
| | - Frank Neese
- Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, P.O. Box 91, H-1521 Budapest, Hungary, and Institut für Physikalische und Theoretische Chemie, Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
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Kadantsev ES, Ziegler T. Implementation of a DFT-Based Method for the Calculation of the Zeeman g-Tensor in Periodic Systems with the Use of Numerical and Slater-Type Atomic Orbitals. J Phys Chem A 2009; 113:1327-34. [DOI: 10.1021/jp805466c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Eugene S. Kadantsev
- Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4 Canada
| | - Tom Ziegler
- Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4 Canada
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25
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Neese F. Spin-Hamiltonian Parameters from First Principle Calculations: Theory and Application. HIGH RESOLUTION EPR 2009. [DOI: 10.1007/978-0-387-84856-3_5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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26
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Rinkevicius Z, de Almeida KJ, Oprea CI, Vahtras O, Ågren H, Ruud K. Degenerate Perturbation Theory for Electronic g Tensors: Leading-Order Relativistic Effects. J Chem Theory Comput 2008; 4:1810-28. [DOI: 10.1021/ct800053f] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Zilvinas Rinkevicius
- Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Katia Julia de Almeida
- Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Cornel I. Oprea
- Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Olav Vahtras
- Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Hans Ågren
- Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Kenneth Ruud
- Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
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27
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Zbiri M. Accurate predictions of the EPR parameters in planar cobalt(II) complexes by hybrid density functional theory. Inorganica Chim Acta 2006. [DOI: 10.1016/j.ica.2006.05.020] [Citation(s) in RCA: 4] [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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Abstract
Starting from the formula proposed by Gerloch and McMeeking in 1975, the electronic g-matrix is expressed as a sum of two matrices called Lambda and Sigma describing the orbital and spin contributions respectively. This approach is applied on benchmark diatomic and triatomic molecules, and on TiF3 and Cu(NH3)4(2+) using either CASPT2 or CCSD(T) methods to calculate the spin-free states and SO-RASSI to calculate spin-orbit coupling. Results compare very well to experimental data and to previous theoretical work; and, for each molecule, the anisotropy of the g-matrix is modeled by the mean of a few parameters.
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Affiliation(s)
- Hélène Bolvin
- Laboratoire de Chimie Quantique, Institut de Chimie de Strasbourg, LC3-UMR 7177, 4 rue Blaise Pascal, 67000 Strasbourg, France.
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Bruna PJ, Grein F. Theoretical Studies on Dications and Trications of FH, ClH, and BrH. Properties of the Bound 15Σ- States. Electron-Spin g-Factors and Fine/Hyperfine Constants of the Metastable X3Σ- States of ClH2+ and BrH2+. J Phys Chem A 2006; 110:4906-17. [PMID: 16599461 DOI: 10.1021/jp0572838] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This theoretical study reports calculations on the fine and hyperfine structure parameters of the metastable X(3)Sigma(-)(sigma(2)pi(2)) state of ClH(2+) and BrH(2+). Data on the repulsive FH(2+) system are also included for comparison purposes. The hyperfine structure (hfs) coupling constants for magnetic (A(iso), A(dip)) and quadrupole (eQq) interactions are evaluated using B3LYP, MP4SDQ, CCSD, and QCISD methods and several basis sets. The fine structure (fs) constants (zero-field splitting lambda and spin-rotation coupling gamma) and electron-spin magnetic moments (g-factor) are evaluated in 2nd-order perturbation theory using multireference CI (MRCI) wave functions. Our calculations find for (35)Cl of ClH(2+) A(iso)/A(dip) = 110/-86 MHz; eQq(0) = -59 MHz; 2lambda = 20.4 cm(-1); g( perpendicular)(v = 0) = 2.02217; and gamma = -0.31 cm(-1) (to be compared with the available experimental A(iso)/A(dip)= 162/-30 MHz). For (79)BrH(2+), the corresponding values are 300/-400 MHz; 368 MHz; 362.6 cm(-1); 2.07302; and -0.98 cm(-1) (experimental 2lambda = 445(+/-80) cm(-1)). We find g( perpendicular)(ClH(2+)) to increase by about 0.0054 between v = 0 and 2, whereas the experimental effective g( perpendicular) changes drastically with vibrational excitation. Nuclear quadrupole coupling constants for halogen atoms X are found to be as large as corresponding A(dip)(X)'s, indicating that both terms may have to be included in the Hamiltonian used to interpret XH(2+) hyperfine spectra. A novel finding relates to the bound character of the 1(5)Sigma(-)(sigmapi(2)sigma) state in FH(2+), as already known for ClH(2+) and BrH(2+), but having a deeper potential well D(e) approximately 4,000 cm(-1) (versus 1,000 cm(-1) in the heavier radicals). Vertical ionization potentials for formation of XH(3+) trications are also discussed.
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Affiliation(s)
- Pablo J Bruna
- Department of Chemistry and Centre for Laser, Atomic and Molecular Sciences, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 6E2
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30
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Grein F. Rare Gas Effects on Hyperfine Coupling Constants of BO, AlO, and GaO. J Phys Chem A 2005; 109:9270-8. [PMID: 16833268 DOI: 10.1021/jp052908n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using density functional theory methods and large basis sets, we calculated hyperfine coupling constants (HFCCs) for the (11)B, (17)O, (27)Al, and (69)Ga nuclei of the radicals BO, AlO, and GaO (XO), embedded in 2-14 rare gas (Rg) Ne and Ar atoms. Kr atoms were included for AlO. The distance of the Rg atoms from XO was varied from 4 to 12 bohr. Matrix effects cause A(iso)(X) to increase, accompanied by decreases in A(dip)(X) and A(dip)(O), while A(iso)(O) remains close to zero. Changes are largest for AlO, slightly smaller for GaO, and very small for BO, in line with the molecular polarizabilities. Observed changes of A(iso)(X) and A(dip)(X) for BO in Ne matrixes and for AlO in Ne, Ar, and Kr matrixes are reproduced in complexes with 12 Rg atoms at distances of 5-6 bohr or 14 Rg atoms at distances of 6-7 bohr. For GaO, experimental data are available only in Ne matrixes. Theoretical results obtained for HFCCs of (17)O could not be verified due to insufficient experimental information. Estimates of HFCCs in matrixes not yet experimentally studied and for GaO in the gas phase have been made. Due to the interaction with rare gas atoms, p-spin density on the X and O atoms of XO is converted into s-spin density on X, thereby causing an increase (in magnitude) of A(iso)(X), accompanied by decreases in A(dip) of X and O. The higher polarizability of XO along the bond axis is reflected in complexes that have axial Rg atoms showing larger changes in HFCCs than comparable complexes without axial Rg atoms.
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Affiliation(s)
- Friedrich Grein
- Department of Chemistry, University of New Brunswick, Fredericton, NB E3B6E2, Canada.
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31
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Grein F. Electron spin resonance g tensors for complexes of Ne and Ar with AlO: theoretical studies related to the large matrix effect observed for AlO. J Chem Phys 2005; 122:124504. [PMID: 15836394 DOI: 10.1063/1.1866095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
For Ne(n)-AlO (n=2, 4, 6, 8, 10) and Ar(n)-AlO clusters (n=2, 4, 6, 8), the perpendicular (relative to AlO) component of the g tensor was calculated by second-order perturbation theory, using multireference configuration-interaction wave functions. The rare-gas (Rg) atoms were placed axially and/or off axially (one or two rings of four Rg atoms each), and the distance of the Rg atoms from the Al and O atoms, or from the AlO axis, was varied from 4 to 12 bohrs. Rg atoms placed axially mostly increase g(perpendicular), whereas off-axially placed ones lower it below the gas-phase value of AlO. The largest deviations from g(perpendicular) of isolated AlO occur at Ne-Al,O distances of 5-6 bohrs, and Ar-Al,O distances of 6-9 bohrs, with maximal lowerings of about 1600 ppm for Ne and about 2200 ppm (estimated) for Ar in the case of two axial and eight off-axial Rg atoms. Electron spin resonance studies by Knight and Weltner found large matrix effects for AlO, with downshifts of g(perpendicular) observed to be about 450 and 1150 ppm in Ne and Ar matrices, respectively.
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Affiliation(s)
- Friedrich Grein
- Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick, E3B6E2 Canada
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Rösch N, Matveev A, Nasluzov VA, Neyman KM, Moskaleva L, Krüger S. Quantum chemistry with the Douglas-Kroll-Hess approach to relativistic density functional theory: Efficient methods for molecules and materials. THEORETICAL AND COMPUTATIONAL CHEMISTRY 2004. [DOI: 10.1016/s1380-7323(04)80038-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Grein F. Trends in EPR g-tensors and hyperfine coupling constants of the isomer pairs HCO/COH, HCS/CSH, HSiO/SiOH and HSiS/SiSH. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2003.09.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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34
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Rinkevicius Z, Telyatnyk L, Sałek P, Vahtras O, Ågren H. Restricted density-functional linear response theory calculations of electronic g-tensors. J Chem Phys 2003. [DOI: 10.1063/1.1620497] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Correlated ab initio calculation of electronic g-tensors using a sum over states formulation. Chem Phys Lett 2003. [DOI: 10.1016/j.cplett.2003.09.047] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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36
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Brownridge S, Grein F. Geometries, Electronic g-tensor Elements, Hyperfine Coupling Constants, and Vertical Excitation Energies for Small Gallium Arsenide Doublet Radicals, GaxAsy (x + y = 3, 5). J Phys Chem A 2003. [DOI: 10.1021/jp035589d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Scott Brownridge
- Department of Chemistry, University of New Brunswick, Fredericton, NB, E3B 6E2, Canada
| | - Friedrich Grein
- Department of Chemistry, University of New Brunswick, Fredericton, NB, E3B 6E2, Canada
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Brownridge S, Grein F, Tatchen J, Kleinschmidt M, Marian CM. Efficient calculation of electron paramagnetic resonance g-tensors by multireference configuration interaction sum-over-state expansions, using the atomic mean-field spin–orbit method. J Chem Phys 2003. [DOI: 10.1063/1.1569243] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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38
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Matveev A, Rösch N. The electron–electron interaction in the Douglas–Kroll–Hess approach to the Dirac–Kohn–Sham problem. J Chem Phys 2003. [DOI: 10.1063/1.1540615] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Bruna PJ, Grein F. Hyperfine coupling constants, electron-spin g-factors and vertical spectra of the X2Σ+radicals BeH, MgH, CaH and BZ+, AlZ+, GaZ+(Z = H, Li, Na, K). A theoretical study. Phys Chem Chem Phys 2003. [DOI: 10.1039/b303698g] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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40
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Bruna PJ, Grein F. Hyperfine coupling constants and electron-sping-factors of B2+, Al2+, Ga2+, BAl+, BGa+, and AlGa+: Anab initiostudy. J Chem Phys 2002. [DOI: 10.1063/1.1487828] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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41
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Neyman KM, Ganyushin DI, Matveev AV, Nasluzov VA. Calculation of Electronic g-Tensors Using a Relativistic Density Functional Douglas−Kroll Method. J Phys Chem A 2002. [DOI: 10.1021/jp0204253] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Konstantin M. Neyman
- Institut für Physikalische und Theoretische Chemie, Technische Universität Munchen, 85747 Garching, Germany
| | - Dmitri I. Ganyushin
- Institut für Physikalische und Theoretische Chemie, Technische Universität Munchen, 85747 Garching, Germany
| | - Alexei V. Matveev
- Institut für Physikalische und Theoretische Chemie, Technische Universität Munchen, 85747 Garching, Germany
| | - Vladimir A. Nasluzov
- Institute of Chemistry and Chemical Technology, Russian Academy of Sciences, 660049 Krasnoyarsk, Russia
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42
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Bruna PJ, Grein F. Theoretical study of the hyperfine coupling constants and electron-spin magnetic moments (g-factors) of X2Σ+ alkali-metal radicals XY± (X,Y=Li,Na,K). Chem Phys 2002. [DOI: 10.1016/s0301-0104(01)00552-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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43
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Neese F. Prediction of electron paramagnetic resonance g values using coupled perturbed Hartree–Fock and Kohn–Sham theory. J Chem Phys 2001. [DOI: 10.1063/1.1419058] [Citation(s) in RCA: 504] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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44
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Ding Z, Gullá AF, Budil DE. Ab initio calculations of electric field effects on the g-tensor of a nitroxide radical. J Chem Phys 2001. [DOI: 10.1063/1.1416177] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Owenius R, Engström M, Lindgren M, Huber M. Influence of Solvent Polarity and Hydrogen Bonding on the EPR Parameters of a Nitroxide Spin Label Studied by 9-GHz and 95-GHz EPR Spectroscopy and DFT Calculations. J Phys Chem A 2001. [DOI: 10.1021/jp0116914] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rikard Owenius
- IFM-Departments of Chemical Physics and Computational Physics, Linköping University, SE-581 83 Linköping, Sweden
| | - Maria Engström
- IFM-Departments of Chemical Physics and Computational Physics, Linköping University, SE-581 83 Linköping, Sweden
| | - Mikael Lindgren
- IFM-Departments of Chemical Physics and Computational Physics, Linköping University, SE-581 83 Linköping, Sweden
| | - Martina Huber
- Huygens Laboratory, MAT Group, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
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Kiljunen T, Eloranta J, Ahokas J, Kunttu H. Magnetic properties of atomic boron in rare gas matrices: An electron paramagnetic resonance study withab initioand diatomics-in-molecules molecular dynamics analysis. J Chem Phys 2001. [DOI: 10.1063/1.1360796] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Bruna PJ, Grein F. Electron-Spin Magnetic Moment (gFactor) of X2Σ+Diatomic Radicals MX(±)with Nine Valence Electrons (M = Be, B, Mg, Al; X = N, O, F, P, S, Cl). An ab Initio Study. J Phys Chem A 2001. [DOI: 10.1021/jp003557+] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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48
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Engström M, Vahtras O, Ågren H. MCSCF and DFT calculations of EPR parameters of sulfur centered radicals. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00961-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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Bruna PJ, Grein F. Ab initio study of the electron-spin magnetic moments (g-factors) of C2−, CSi−, Si2−, LiC2, NaC2, and LiSi2. J Chem Phys 2000. [DOI: 10.1063/1.481723] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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50
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Lushington GH. Small Closed-Form CI Expansions for Electronic g-Tensor Calculations. J Phys Chem A 2000. [DOI: 10.1021/jp9937656] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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