Toward a Balanced Description of Ground and Excited States with Transcorrelated F12 Methods.

ABSTRACT: By correlating only the 1-particle states occupied in the reference determinant, the conventional design for the single-reference R12/F12 explicitly correlated methods biases them toward the ground-state description, thereby making the treatment of response properties of the ground state, and energies and other properties of excited states less robust. While the use of multireference methods and/or extensions of the standard SP-projected geminals can achieve a more balanced description of ground and excited states, here we show that the same goals can be achieved by extending the action of F12 correlators to the occupied and valence unoccupied 1-particle states only. This design choice reflects the strong dependence of the optimal correlation length scale of the F12 ansatz on the orbital e

SUBMITTER: Masteran C 

PROVIDER: S-EPMC12573748 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature