Distance reduction factor in the modified El-Hoshy−Gibbons model determined as a function of Kohn−Sham radii of low-velocity projectiles and impact parameters of targets for small-angle collisions

Abstract Distance reduction factor y of the impact parameter R 0 (for small-angle collisions) in the modified El-Hoshy−Gibbons model had been defined in the case a Kohn−Sham radius r KS of a low-velocity projectile being larger or smaller than R 0 , but not in the case r KS ≈ R 0 . Taking the case of small difference (i.e. 1%) between r KS and R 0 (namely, B along the GaN 〈0001〉 direction), we suggested y of 5exp[−60( r KS − R 0 )/ R 0 ] + 3 in the case 0.001 ≤ ( r KS − R 0 )/ R 0 and 8 in the case ( r KS − R 0 )/ R 0 < 0.001. Additional careful experiments should expand the options for selecting projectiles for channeled-ion implantation into targets.