A theoretical study of SiCN and SiNC in the X˜2Πelectronic state based on global potential energy surfaces

► We determine global potential energy surfaces of SiCN in the ground state. ► We assign vibrational wave functions computed up to 360 levels for the ground state. ► The Renner parameters are evaluated for linear SiCN and SiNC. ► The Renner-Teller effect on the vibronic energy is negligible for the J = 1 states. ► The spin-orbit effects are negligible in the vibrational levels.