Collect. Czech. Chem. Commun. 1980, 45, 1317-1322

On the qualitative theory of Shockley surface states of the (111) face of NbC and the nature of bonding in this compound

Mojmír Tomášeka, Štěpán Picka and Karlheinz Schwarzb

a J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2
b Institut fur Technische Elektrochemie, Technische Universitat, Wien, A 1060 Vienna, Austria


Qualitative theory of Shockley surface states is applied to the analysis of the (111) surface of the niobium carbide crystal. The existence of Shockley states is predicted in two hybridizational gaps. One of (p, t2g) character lies just below the Fermi energy and the other of (eg, t2g) character is at higher energies. The relation between Shockey states and bonding is discussed. A strong (p, t2g) covalent component of the metal-nonmetal bond is found.