Study on the potential energy function and spectroscopic constants for the ground state(X~1Σ~+ ) of SiO_2,SiS molecule

The electronic states of the ground state dissociation limit of SiO,SiS molecule are correctly determined based on group theory and atomic and molecular reaction statics.The structural optimization for the ground state(X~1∑~+)of SiO,SiS molecule has been calculated using density functional theory B3P LY and B3P86 method with the basis sets 6-Zll + +G(3df,2pd) and D95(3df,2pd).The potential curve of the ground state is scanned by using B3P86/ D95(3df,2pd).The potential energy function and relevant spectroscopic constants of this state are obtained by fitting to the Murrell-Sorbie function. The result shows that the spectroscopic constants derived from the Murrell-Sorbie function are in very good agreement with the experimental data,which indicated that the Murrell-Sorbie function can correctly present the potential energy function of the ground state of SiO,SiS molecule.