Computational study of molecular hydrogen in zeolite Na-A. II. Density of rotational states and inelastic neutron scattering spectra

Part I of this series [J. Chem. Phys. 111, 7599 (1999)] describes a simulat ion of H-2 adsorbed within zeolite Na-A in which a block Lanczos procedure is used to generate the first several (9) rotational eigenstates of H-2, mo deled as a rigid rotor, and equilibrated at a given temperature via Monte C arlo sampling. Here, we show that rotational states are strongly perturbed by the electrostatic fields in the solid. Wave functions and densities of r otational energy states are presented. Simulated neutron spectra are compar ed with inelastic neutron scattering data. Comparisons are made with IR spe ctra in which rotational levels may appear due to rovibrational coupling. ( C) 2001 American Institute of Physics.