Chemical bond effects on the low-energy electronic stopping power of protons: use of molecular fragments

Abstract

We propose the use of molecular fragments in a recently derived modified version of the Firsow model to account for the low-energy electronic stopping cross section due to molecular targets. The method is free of adjustable parameters and is based on the floating spherical Gaussian (FSGO) representation of molecular orbitals, being particularly useful for the treatment of large molecular targets. The results of this work indicate fair agreement with other calculations for protons incident on a wide variety of systems. Support is given to both, the use of characteristic molecular groups as well as the core and bond (CAB) partition scheme for the stopping power analysis of compound materials.