We introduce a practical approach for computing the Breit–Pauli spin–orbit matrix elements of multiconfigurational systems with both spin and spatial degeneracies based on our recently developed RAS-nSF-IP/EA method (Houck, S. E.; et al. J. Chem. Theory Comput. 2019, 15, 2278). The spin–orbit matrix elements over all the multiplet components are computed using a single one-particle reduced density matrix as a result of the Wigner–Eckart theorem. A mean field spin–orbit approximation was used to account for the two-electron contributions. Basis set dependence as well as the effect of including additional excitations is presented. The effect of correlating the core and semicore orbitals is also examined. Surprisingly accurate results are obtained for spin–orbit coupling constants, despite the fact that the efficient wave function approximations we research neglect the bulk of dynamical correlation.
Meitei, Oinam Romesh, et al. "Spin–Orbit Matrix Elements for a Combined Spin-Flip and IP/EA approach." Journal of Chemical Theory and Computation, vol. 16, no. 6, Apr. 2020. https://doi.org/10.1021/acs.jctc.0c00103
Meitei, Oinam Romesh, Houck, Shannon E., & Mayhall, Nicholas J. (2020). Spin–Orbit Matrix Elements for a Combined Spin-Flip and IP/EA approach. Journal of Chemical Theory and Computation, 16(6). https://doi.org/10.1021/acs.jctc.0c00103
Meitei, Oinam Romesh, Houck, Shannon E., and Mayhall, Nicholas J., "Spin–Orbit Matrix Elements for a Combined Spin-Flip and IP/EA approach," Journal of Chemical Theory and Computation 16, no. 6 (2020), https://doi.org/10.1021/acs.jctc.0c00103
@article{osti_1631163,
author = {Meitei, Oinam Romesh and Houck, Shannon E. and Mayhall, Nicholas J.},
title = {Spin–Orbit Matrix Elements for a Combined Spin-Flip and IP/EA approach},
annote = {We introduce a practical approach for computing the Breit–Pauli spin–orbit matrix elements of multiconfigurational systems with both spin and spatial degeneracies based on our recently developed RAS-nSF-IP/EA method (Houck, S. E.; et al. J. Chem. Theory Comput. 2019, 15, 2278). The spin–orbit matrix elements over all the multiplet components are computed using a single one-particle reduced density matrix as a result of the Wigner–Eckart theorem. A mean field spin–orbit approximation was used to account for the two-electron contributions. Basis set dependence as well as the effect of including additional excitations is presented. The effect of correlating the core and semicore orbitals is also examined. Surprisingly accurate results are obtained for spin–orbit coupling constants, despite the fact that the efficient wave function approximations we research neglect the bulk of dynamical correlation.},
doi = {10.1021/acs.jctc.0c00103},
url = {https://www.osti.gov/biblio/1631163},
journal = {Journal of Chemical Theory and Computation},
issn = {ISSN 1549-9618},
number = {6},
volume = {16},
place = {United States},
publisher = {American Chemical Society},
year = {2020},
month = {04}}