Bragg's Additivity Rule and Core and Bond model studied by real-time TDDFT electronic stopping simulations: the case of water vapor

Abstract

The electronic stopping power ( ) of water vapor, hydrogen and oxygen gases for protons were calculated with rt-TDDFT simulations.• With geometrically pre-sampled nm-long ion trajectories, the averaged value of rt-TDDFT converged quickly.The results were compared with observations.• For rt-TDDFT , the validity of Bragg's additivity rule (BAR) of 2H 2 + O 2 → 2H 2 O was found to be applicable for > 40 keV/amu.• The core and bond (CAB) contributions to were calculated from rt-TDDFT simulations, and found smaller than SRIM values.