complete active space self-consistent field second-order perturbation theory (CASPT2)

https://doi.org/10.1351/goldbook.CT07344
Theoretical scheme suitable for computations of accurate excitation energies and reaction barriers. In the first step, @[email protected] is taken into account only to a certain extent by using a CASSCF formalism (the so called non-dynamic correlation), whereas the remaining @[email protected] (the so called dynamic correlation) is included through the use of second-order @[email protected]
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 316 [Terms] [Paper]