A b i n i t i o calculation of near-equilibrium potential and multipole moment surfaces and vibrational frequencies of H+3 and its isotopomers

H+3 potential energies and multipole moments are calculated from a full CI with a 10s, 4p, 2d GTO hydrogen basis. 69 calculated energy points with energies of up to 25 000 cm−1 above the minimum are fitted by a power series expansion in terms of a Morse-type coordinate with a mean square error of less than 1 cm−1. Rotationless vibrational states with energies of up to 12 000 cm−1 above equilibrium are calculated variationally for ten isotopomers. The resulting band origins for the seven analyzed fundamental transitions show a mean deviation of less than 2 cm−1. For the other predicted frequencies, the errors are expected to be below 0.1% also. The equilibrium bond length of H+3 is predicted to be 0.8732(2) Å.