Hybrid Gaussian–discrete-variable representation for one- and two-active-electron continuum calculations in molecules

Abstract

A combined basis of analytic Gaussian functions and grid-based finite element-discrete variable representation spherical harmonic expansion is specialized for the description of continuum electron dynamics in the presence of electrons held fixed in core molecular orbitals. The applicability of this hybrid representation designed for general problems involving accurate determination of molecular continua wave functions is illustrated for photoionization of second-row diatomic molecules. Accurate descriptions of such electron continuum dynamics are a necessary step towards analyzing correlated double continua photoejections. Examination of this hybrid method in comparison to a more computationally expensive pure grid-based single-center expansion reveals several key advantages that by design make it attractive for describing processes involving one or more electrons moved to the continuum.