Extension of renormalized coupled-cluster methods including triple excitations to excited electronic states of open-shell molecules.
The general-purpose open-shell implementation of the completely renormalized equation-of-motion coupled-cluster approach with singles, doubles, and noniterative triples [CR-EOMCCSD(T)] is reported. Benchmark calculations for the low-lying doublet and quartet states of the CH radical show that the CR-EOMCCSD(T) method is capable of providing a highly accurate description of ground and excited states of open-shell molecules. This includes states with strong double excitation character, for which the conventional EOMCCSD approach fails.
Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
Marta
M
Włoch
Jeffrey R
JR
Gour
Karol
K
Kowalski
Piotr
P
Piecuch