A first principle study on the geometry and the electronic structures of VC(001) relaxed surface

Abstract

By using the first principle method, the geometry and electronic structures of the clean VC(001) surface are investigated. Similar to the TiC(001) surface, the relaxation of the VC(001) surface leads to the C and V atoms on the top layer move outward and inward, respectively. Results of band structure calculation show that the band structures of transition metal (001) surfaces can be well described by the rigid band model. For the VC(001) surface, the surface states are mainly located around 30eV below the Fermi level, and mainly originate from the 2pz orbital of C atom in the top layer. In addition, the surface states derived from the top layer V 3d orbitals are also observed near the Fermi level. Since these states contain significant contributions of those 3d orbitals vertical to the surface (3d２z and 3dxz/dyz), which will play important roles in the surface reactions, it could be expected that the VC(001) surface exhibits different surface reactivity compared with the TiC(001) surface.