Nature of chemisorption on titanium carbide and nitride

Extensive density-functional calculations are performed to understand atomic chemisorption on the TiC(1 1 1) and TiN(1 1 1) surfaces, in particular the calculated pyramid-shaped trends in the adsorption energies for second- and third-period adatoms. Our previously proposed concerted-coupling model for chemisorption on TiC(1 1 1) is tested against new results for adsorption on TiN(1 1 1) and found to apply on this surface as well, thus reflecting both similarities and differences in electronic structure between the two compounds.