A theoretical study on S-loss photodissociation of the CS2+ ion

The CASPT2 potential energy curves for S-loss dissociation from the X-2 Pi(g), A(2)Pi(u), B-2 Sigma(+)(u), C-2 Sigma(+)(g), 1(4)Sigma, 1(4)Pi, 1(2)Sigma, and 2(4)Sigma states of the CS2+ ion were calculated. A conical intersection point between the B-2 Sigma(+)(u) and C-2 Sigma(+)(g) potential energy surfaces was found. At the CASSCF level we located the minimum energy crossing points (MECPs) for the X-2 Pi(g)/1(4)Sigma, A(2)Pi(u)/1(4)Sigma, B-2 Sigma(+)(u)/1(4)Sigma, C-2 Sigma(+)(g)/1(4)Sigma, A(2)Pi(u)/1(2)Sigma, and B-2 Sigma(+)(u)/1(2)Sigma state-pairs and calculated spin-orbit coupling values. MECP for the C-2 Sigma(+)(g)/1(2)Sigma state-pair was not found. We suggest photodissociation processes via A(2)Pi(u) and B-2 Sigma(+)(u). Photodissociation mechanisms via A(2)Pi(u), B-2 Sigma(+)(u), and C-2 Sigma(+)(g) proposed in the previous experimental studies are discussed. (C) 2009 Elsevier B. V. All rights reserved.