AN EFFICIENT GRID CALCULATION OF VIBRATIONAL-STATES FOR H-3-ASTERISK WITH GEOMETRIC PHASE IN HYPERSPHERICAL COORDINATES

We report the J = 0 calculations of vibrational energy levels of the f irst excited state of H-3 with the consideration of geometric phase ef fects. A pseudo-spectral technique and a mixed grid and nondirect prod uct basis method have been used in hyperspherical coordinates. The act ion of the Hamiltonian on the wavefunction is performed by the fast Fo urier transform for rho and phi variables and the pseudo-inverse DVR-F BR transform for theta. The nondirect product hyperspherical harmonics describe correctly the boundary conditions of vibrational states at t heta = 0. (C) 1997 Elsevier Science B.V.