Optimized reaction paths for as obtained from MRCI+Q/aVQZ//CASSCF/aVQZ calculations. The reaction coordinate is defined as R_CS −R_CC. In the bottom panel, the valence angle, γ_CCS, was held fixed at 179.9° in the geometry optimizations, while, in the top panel, it was freely optimized along with R_CS or R_CC bond distances. Two ³A″ and one ³A′ triplet electronic states of CCS were considered in each case.