Extended multi-state CASPT2

Extended multistate CASPT2 (XMS-CASPT2) [see T. Shiozaki, W. Gyorffy, P. Celani, and H.-J. Werner, Communication: The extended multi-state CASPT2 method: Energy and nuclear gradients, J. Chem. Phys. 135, 081106 (2011)] provides a better description of near degenerate situations and avoided crossings. Currently this option is available only with the RS2 code, not for RS2C.

molpro@molpro.net 2018-11-18