A theoretical study of the low-lying electronic states of SC3

Abstract A theoretical study of the excited electronic states of the SC 3 system has been carried out by means of density functional (B3LYP) and ab inito methods (QCI, MRCI, RHF-CC) in combination with relatively large basis sets. The structures of several singlet and triplet species are reported, together with their vibrational frequencies and infrared intensities. The electronic structures are analyzed by means of the natural bond orbital (NBO) method. The vertical electronic excitation energies and oscillator strengths of the ground state SCCC ( 1 Σ + ) have also been computed. The lowest-energy allowed transitions are X 1 Σ + → C 1 Π and X 1 Σ + → D 1 Σ + , and should have comparable intensities.