Spin-Flip TDDFT within the Sternheimer Formulation: A Gaussian and Plane Wave Implementation.

ABSTRACT: We report the first implementation of spin-flip time-dependent density functional theory (SF-TDDFT) within the Tamm-Dancoff approximation in the Sternheimer formulation including the use of the noncollinear kernel. The noncollinear kernel was stabilized by introducing a screening method for the numerical integration, realizing a robust scheme of excited energy and gradient calculations of SF-TDDFT using generalized gradient approximation functionals. The implementation is evaluated by benchmark calculations of vertical excitation energies and optimized molecular geometries. The benchmark for vertical excitations consists of 19 excitations with high level of theory reference data from the QUESTDB. An underestimation of vertical excitation energies was observed for the PBE and PBE0 functiona

SUBMITTER: Hernandez-Segura LI 

PROVIDER: S-EPMC12557386 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature