Toward Accurate Spin-Orbit Splittings from Relativistic Multireference Electronic Structure Theory.

ABSTRACT: Most nonrelativistic electron correlation methods can be adapted to account for relativistic effects, as long as the relativistic molecular spinor integrals are available, from either a four-, two-, or one-component mean-field calculation. However, relativistic multireference correlation methods remain a relatively unexplored area, with mixed evidence regarding the improvements brought by perturbative treatments. We report, for the first time, the implementation of state-averaged four-component relativistic multireference perturbation theories to second and third order based on the driven similarity renormalization group (DSRG). With our methods, named 4c-SA-DSRG-MRPT2 and 3, we find that the dynamical correlation included on top of 4c-CASSCF references can significantly improve the spin-o

SUBMITTER: Zhao Z 

PROVIDER: S-EPMC11261625 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature