Spin-flip equation-of-motion coupled-cluster electronic structure method for a description of excited states, bond breaking, diradicals, and triradicals.
The spin-flip (SF) approach to multireference situations (e.g., bond breaking, diradicals, and triradicals) is described. Both closed- and open-shell low-spin states are described within a single reference formalism as spin-flipping, e.g., alpha --> beta, excitations from a high-spin reference state for which both dynamical and nondynamical correlation effects are much smaller than for the corresponding low-spin state. Formally, the SF approach can be viewed as an equation-of-motion model, where target states are sought on the basis of determinants conserving the total number of electrons but changing the number of alpha and beta electrons.
Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA. krylov@usc.edu
Anna I
AI
Krylov