Ab initio vibrational spectra and structure of the ground state of HeScH²⁺

Abstract

Potential energy and dipole moment surfaces of the ¹A′ ground state of HeScH²⁺ have been calculated using both the internally contracted single and double excitation multireference configuration interaction and the coupled-cluster singles and doubles augmented by a perturbative treatment of triple excitations levels of theory. Analytical functions have been fitted to the discrete surfaces employing a multidimensional least squares approach. These analytical functions have subsequently been embedded within a rectilinear normal-coordinate vibrational Hamiltonian in order to calculate vibrational states and transition intensities for low-lying states of HeScH²⁺.

Acknowledgments

The authors wish to acknowledge the generous allocation of CPU resources from APAC, ac³ and The University of Newcastle. DJDW wishes to acknowledge receipt of an Australian Postgraduate Research Award.