A new four-dimensional potential energy surface of the Ar–CS2 complex: Dependence on the symmetric and antisymmetric stretching vibrations of CS2

Highlights: • A new ab initio PES involving the Q₁ and Q₃ normal modes of CS₂ is constructed. • Each potential has a T-shaped global minimum and two equivalent local minima. • The shift of the Ar–CS₂ complex in the ν₁ + ν₃ region is first reported. A high quality four-dimensional intermolecular PES for Ar–CS₂ involving the Q₁ and Q₃ normal modes for the ν₁ symmetric stretching vibration and ν₃ antisymmetric stretching vibration of CS₂ is presented. Two vibrationally averaged potentials with CS₂ at the vibrational ground and ν₁ + ν₃ excited states are generated from the four-dimensional potential. Each potential has a T-shaped global minimum and two equivalent linear minima. The radial DVR/angular FBR method and the Lanczos algorithm are applied to calculate the rovibrational energy levels and bound states. The predicted band origin shift of the complex is −0.0495 cm⁻¹. The spectroscopic parameters are also predicted.