On the combination of ECP-based CI calculations with all-electron spin-orbit mean-field integrals

Schimmelpfennig, Bernd; Maron, Laurent; Wahlgren, Ulf; Teichteil, Christian; Fagerli, Hilde; Gropen, Odd

doi:10.1016/s0009-2614(98)00121-3

Cited by 68 publications

(20 citation statements)

References 27 publications

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“…In this case, the radial components of the SOC operator (12) are chosen to be analytical functions of the form whose parameters \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$\{B^{n \ell, I}_{k}, \beta_{ k}^{n \ell, I}\}$\end{document} are determined through least‐squares fitting to the radial parts of the numerical Wood–Boring spin‐orbit operator of an atom I 73. The SOMF Hamiltonian has been used, too, in combination with effective core potentials 74,75. In this case, one has to make sure that a close correspondence exists between the valence orbitals of the all‐electron and the effective core potential calculations.…”

Section: Spin–orbit Couplingmentioning

confidence: 99%

Spin–orbit coupling and intersystem crossing in molecules

Marian

2011

WIREs Comput Mol Sci

724

799

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Many light‐induced molecular processes involve a change in spin state and are formally forbidden in non‐relativistic quantum theory. To make them happen, spin–orbit coupling (SOC) has to be invoked. Intersystem crossing (ISC), the nonradiative transition between two electronic states of different multiplicity, plays a key role in photochemistry and photophysics with a broad range of applications including molecular photonics, biological photosensors, photodynamic therapy, and materials science. Quantum chemistry has become a valuable tool for gaining detailed insight into the mechanisms of ISC. After a short introduction highlighting the importance of ISC and a brief description of the relativistic origins of SOC, this article focusses on approximate SOC operators for practical use in molecular applications and reviews state‐of‐the‐art theoretical methods for evaluating ISC rates. Finally, a few sample applications are discussed that underline the necessity of studying the mechanisms of ISC processes beyond qualitative rules such as the El‐Sayed rules and the energy gap law. © 2011 John Wiley & Sons, Ltd. This article is categorized under: Structure and Mechanism > Molecular Structures

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Section: Spin–orbit Couplingmentioning

confidence: 99%

Spin–orbit coupling and intersystem crossing in molecules

Marian

2011

WIREs Comput Mol Sci

724

799

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“…For all wavefunction models of type   ,   and   (see next paragraph for model definitions) we used the exact two-component Hamiltonian scheme of Iliaš and Saue [50] where two-electron spin-same-orbit (SSO) and spin-other-orbit (SOO) corrections were either obtained by means of atomic mean-field integrals [51,52] (amf) or in a molecular mean-field approach [53] (mmf), based on the X2C transformation of the converged four-component Fock operator. For the models   and   molecular spinors were optimized through all-electron four-component Dirac-Coulomb Hartree-Fock calculations.…”

Section: Technical Detailsmentioning

confidence: 99%

Theoretical study on ThF⁺, a prospective system in search of time-reversal violation

et al. 2015

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The low-lying electronic states of ThF + , a possible candidate in the search for and  -violation, have been studied using high-level correlated relativistic ab initio multi-reference coupled-cluster and configuration interaction approaches. For the Δ 3 state component with Ω = 1 (electron electric dipole moment 'science state') we obtain an effective electric field of = E 35.2 eff − 1 ), challenging the state assignment from an earlier theoretical study on this species (Barker et al 2012 J. Chem. Phys. 136 104305).e 29 cm. This value is more than 16 times smaller than the most constraining upper bound from an atomic study [12]. Charged molecules offer an experimental advantage over neutral OPEN ACCESS RECEIVED

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“…At the SCF level the error due to this neglect of twoelectron picture change can be reduced by constructing corrections to the untransformed two-electron term from atomic contributions. One example is the AMFI approach 30,31 in which the spin same-orbit and spin other-orbit contributions at the free-particle ͑2e-FP͒ level, arising from the Coulomb and Gaunt terms, respectively, 55 are constructed in a meanfield fashion based on spin-free second-order DKH atomic calculations. A straightforward improvement of this procedure, which also allows the inclusion of scalar relativistic corrections, is to rather construct these atomic contributions from an exact picture change transformation of the corresponding converged atomic HF or KS matrices.…”

Section: The Two-electron Interaction In a Two-component Relativismentioning

confidence: 99%

The molecular mean-field approach for correlated relativistic calculations

Sikkema

Visscher

Saue³

et al. 2009

The Journal of Chemical Physics

225

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A new approach for relativistic correlated electron structure calculations is proposed by which a transformation to a two-spinor basis is carried out after solving the four-component relativistic Hartree-Fock equations. The method is shown to be more accurate than approaches that apply an a priori transformation to a two-spinor basis. We also demonstrate how the two-component relativistic calculations with properly transformed two-electron interaction can be simulated at the four-component level by projection techniques, thus allowing an assessment of errors introduced by more approximate schemes.

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On the combination of ECP-based CI calculations with all-electron spin-orbit mean-field integrals

Cited by 68 publications

References 27 publications

Spin–orbit coupling and intersystem crossing in molecules

Spin–orbit coupling and intersystem crossing in molecules

Theoretical study on ThF⁺, a prospective system in search of time-reversal violation

The molecular mean-field approach for correlated relativistic calculations

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On the combination of ECP-based CI calculations with all-electron spin-orbit mean-field integrals

Cited by 68 publications

References 27 publications

Spin–orbit coupling and intersystem crossing in molecules

Spin–orbit coupling and intersystem crossing in molecules

Theoretical study on ThF+, a prospective system in search of time-reversal violation

The molecular mean-field approach for correlated relativistic calculations

Contact Info

Product

Resources

About

Theoretical study on ThF⁺, a prospective system in search of time-reversal violation