Adsorption of He and Ne on regular, irregular and defected surfaces of LiHcrystal: ab initio study

An attempt has been made to simulate LiH crystal surface and to examine the binding energies and configurations of He and Ne on regular (flat), irregu lar (kinks and steps) and defected (cation vacancies, F+, F and F-) surface s using the Hartree-Fock SCF and second order Moller-Plesset perturbation m ethods of ab initio theory. The adatom-surface interactions were modified d ramatically in the presence of irregular and defected surfaces and the most stable adsorption was associated with the cation vacancies, anion vacancie s as well as the cation three-coordinated kinks above which the adatoms wer e tilted 45 degrees away from the surface normal. Repulsive interactions an d steric constraints are shown to play the dominant role. (C) 1999 Elsevier Science Ltd. All rights reserved.