Quantum ab initio study of acetylene adsorption on NaCl(100) .1. Topology and adsorption energy

The quantum periodic Hartree-Fock study of acetylene adsorption on the NaCl(100) surface is carried out for three model structures, the admolecule being parallel or perpendicular to the surface. Two surface coverages (tau = 1/4 and 1) are investigated for these three adsorption sites. In the most favorable situation, the adsorption energy for the monolayer is calculated as 8.0 kcal mol(-1). The lateral interaction is extrapolated to 1.6 kcal mol(-1) by surface coverage analysis. These calculated results are in good agreement with the experiment values. The approaches are discussed and compared to a semi-classical study of acetylene adsorption on MgO(100). (C) 1997 Elsevier Science B.V.