Hyperfine Coupling Constants in Local Exact Two-Component Theory
| Autor: | Yannick Franzke, Jason Yu |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Journal of Chemical Theory and Computation. 18:323-343 |
| ISSN: | 1549-9626 1549-9618 |
| DOI: | 10.1021/acs.jctc.1c01027 |
| Popis: | We present a highly efficient implementation of the electron-nucleus hyperfine coupling matrix within the one-electron exact two-component (X2C) theory. The complete derivative of the X2C Hamiltonian is formed, that is, the derivatives of the unitary decoupling transformation are considered. This requires the solution of the response and Sylvester equations, consequently increasing the computational costs. Therefore, we apply the diagonal local approximation to the unitary decoupling transformation (DLU). The finite nucleus model is employed for both the scalar potential and the vector potential. Two-electron picture-change effects are modeled with the (modified) screened nuclear spin-orbit approach. Our implementation is fully integral direct and OpenMP-parallelized. An extensive benchmark study regarding the Hamiltonian, the basis set, and the density functional approximation is carried out for a set of 12-17 transition-metal compounds. The error introduced by DLU is negligible, and the DLU-X2C Hamiltonian accurately reproduces its four-component "fully" relativistic parent results. Functionals with a large amount of Hartree-Fock exchange such as CAM-QTP-02 and ωB97X-D are generally favorable. The pure density functional r |
| Databáze: | OpenAIRE |
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