Interatomic potential in solids and its applications to range calculations

Abstract

Abstract Using the Gordon-Kim statistical model, the hetero-nuclear potentials have been numerically evaluated from the first principle for variousZ 1—Si combinations, where the charge distribution of the solid-state atom is constructed from the charge density of the Dirac-Hartree-Fock-Slater gas-state atom. The corresponding projected ranges in silicon are calculated using the Monte Carlo simulation code ACAT. For ε = 0.09 the calculated ranges show a little weaker Z1 oscillation than the experimental data, but they reproduce reasonably the experimental projected ranges. The convenient combination rule for constructing the hetero-nuclear potential from the corresponding homo-nuclear potentials is proposed. This combination rule is shown not only to reproduce well the hetero-nuclear potential which is calculated from the first principle, but also to yield the reasonable projected range. The analytic universal function is also proposed averaging the various homo-nuclear potentials, and it is found that the projected ranges calculated from the present universal screening function show a good agreement with the Kr-C range at low energies.