Ab initio potential energy surface, electric-dipole moment, polarizability tensor, and theoretical rovibrational spectra in the electronic ground state of 14NH3+

We report the calculation of a six-dimensional CCSD(T)/aug-cc-pVQZ potential energy surface for the electronic ground state of NH3+ together with the corresponding CCSD(T)/aug-cc-pVTZ dipole moment and polarizability surface of 14NH3+. These electronic properties have been computed on a large grid of molecular geometries. A number of newly calculated band centers are presented along with the associated electric-dipole transition moments. We further report the first calculation of vibrational matrix elements of the polarizability tensor components for 14NH3+; these matrix elements determine the intensities of Raman transitions. In addition, the rovibrational absorption spectra of the ν2, ν3, ν4, 2ν2-ν2, and ν2+ν3-ν2 bands have been simulated.