Electronic properties of ThC^- and ThC

The present study investigates the properties of low-lying states of ThC^- and ThC using correlated wave function theories. To this end, we employed multireference calculations and various coupled-cluster approaches in combination with large correlation-consistent basis sets. These methods were applied to examine potential energy curves (PECs), electron configurations, energetics, spectroscopic constants, and spin-orbit coupling effects for 9 states of ThC^- and 18 states of ThC. The ground states of ThC^- and ThC were identified as single-reference ²Σ+1/2(I) and , respectively. Electron detachment from the 7s orbital of the Th center in ThC^- [²Σ⁺(I); 1σ²2σ¹3σ²1π⁴] yields ThC [³Σ⁺(I); 1σ²2σ¹3σ¹1π⁴]. The calculated adiabatic detachment energy (ADE) and vertical detachment energy (VDE) for this process are 1.591 and 1.604 eV, respectively. Furthermore, the dissociation energy (D₀) of ThC [] is predicted to be 5.099 eV. The standard enthalpy of formation, (298 K), of ThC is estimated to be 822.52 ± 6 kJ mol^-1.