We report the calculation of a six-dimensional CCSD(T)/aug-cc-pVQZ potential energy surface for the electronic ground state of NH+3 together with the corresponding CCSD(T)/aug-cc-pVTZ dipole moment and polarizability surface of 14NH+3 . 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 rst calculation of vibrational matrix elements of the polarizability tensor components for 14NH+3 ; these matrix elements determine the intensities of Raman transitions. In addition, the rovibrational absorption spectra of the 2, 3, 4, 2 2 􀀀 2, and 2 + 3 􀀀 2 bands have been simulated.