DW-SA-cCASSCF(2,2)-2site

dynamically-weighted state-averaged constrained complete active space (2e,2o) for 2 site Anderson-Holstein model

This code does electronic structure calculation for 2-site Anderson-Holstein model, including calculating adiabatic CAS(2,2) potential energy surfaces (PESs), calculating relaxation between CAS(2,2) states and the corresponding electron-hole-pair (EHP) excitation states, and diabatizing CAS(2,2) states. Different from the 1site code, we use newton-kkt algorithm to deal with the 2-site orbital optimization problem with constraint. This methodology should be easily extended to a multiple impurity site model.