Forecasting the stable isomers of [Si, C, S]+ and [Si, C, S]- systems

The doublet potential energy surfaces of [Si, C, S](+) and [Si, C, S](-) systems were investigated by the DFT, QCISD, and CCSD(T) methods. At the QCISD/6-311 +G(d) level, it is shown that a total of 3 minimum isomers are connected by 2 transitional states and 4 minimum isomers are connected by 2 transitional states for [Si, C, S](+) and [Si, C, S](-) systems, respectively. Through an analysis of thermodynamic and kinetic stabilities, there is a linear doublet isomer [Si-C-S](+) located as the stable isomer in [Si, C, S](+) system. In doublet [Si, C. S](-) system, two stable isomers are located, which are a linear [Si-C-S] and a three-membered ring form c-[SiCS](-).