Bond-length analysis of the omega structure in Ti, Zr, Hf and their alloys: experimental data, new correlations and implications for chemical bondingmodels

An analysis is performed of the experimental information on the key interat omic distances (IDs) of the AlB2 type structure, the so-called omega (Omega ) phase in Ti and Zr, as well as in Ti-V and Zr-Nb alloys. Various remarkab le correlations are found between these IDs and standard measures of the at omic size, and with Pauling's bond-lengths. These observations are discusse d in the light of the phenomenological bonding pictures of the Omega struct ure, and with our recent ab initio calculations of the electronic structure of this phase. (C) 1999 Elsevier Science S.A. All rights reserved.