Electronic Structure of TiB2 under High Pressures

The electronic structures of TiB2 in compression have been calculated by using the self-consistent LMTO-ASA method. All the relativistic effects except spin-orbit coupling are considered. The results indicate that as the degree of compression increases, Ti-B hybridization is enhanced and another pseudogap or deep valley in the electronic structure appears. This pseudogap is connected with the increased cohesion of crystal under high pressure. Charge transfer from Ti to B decreases with increase of compression, though this effect is insignificant within the compression range considered.