CUBIC-GRID GAUSSIAN-BASIS SETS FOR ELECTRON-SCATTERING CALCULATIONS .6. APPLICATIONS TO H-2, H2O, AND CH4

We present a vibrational electron energy loss spectrum (EELS) of neat solid methane, with partially resolved bands for nu(4) and nu(2) excit ations. The intensities of the observed bands are well reproduced by s cattering calculations performed by the recently developed cubic-grid Gaussian basis set (CGGBS) method. For testing the CGGBS method we als o used literature data on elastic electron scattering by methane and d ata on elastic and vibrational inelastic electron scattering by H-2 an d H2O. We present a procedure for the analytical differentiation of th e scattering amplitude with respect to normal coordinates.