Accurate Computation of Vibronic Energies and of Some Expectation Values for H2, D2, and T2

The complete four-particle nonrelativistic Hamiltonian and 147-term wavefunctions have been used to compute the energies and the expectation values of several other operators for vibronic ground states and for the first vibrationally excited states of H2, D2, and T2. For H2 and D2 the computed dissociation energies, with relativistic corrections, are by 0.6 and 1.3 cm—1, respectively, larger than the experimental values.