Quantum dynamics from ab initio points

lIn this paper, we explore the numerical feasibility of carrying out quantu m dynamics calculations from ab initio points for gas phase chemical reacti ons. In this approach, the ab initio data are first generated from quantum chemistry programs on a coarse numerical grid and a quantum dynamics calcul ation is then carried out using data from these grids. A crucial step in th e success of this method is the application of a sequential one-dimensional fitting approach (SOFA) to give potential energy information off the origi nal numerical grid. Using the SOFA scheme, one avoids the traditional and o ften intractable task of fitting a global potential energy surface from the ab initio data. In the present paper, a numerical test of this approach is reported for time-dependent wavepacket calculation for the prototype H + H -2 reaction.