Geometric and Electronic Structures of CrSin−/0/+ (n = 1-3) Clusters from DMRG-CASPT2 Calculations

Abstract The DMRG-CASPT2, CASPT2, and density functional theory (DFT) were applied to investigate the electronic states of the relevant isomers of CrSin−/0/+ (n = 1-3) clusters. To obtain reliable relative energies of the electronic states and the electron detachment energies, the active spaces of DMRG-CASPT2 are extended to 20, 22, and 23 orbitals for CrSin−/0/+ (n = 1-3) clusters. The bond distances, vibrational frequencies, and relative energies of the electronic states of CrSin−/0/+ (n = 1-3) clusters are reported. The calculated electron detachment energies are employed to interpret the photoelectron spectrum of CrSi3− cluster.