Equation of state parameters for stable and non-stable transition metal phases from universal binding Energy relations

Remarkable regularities in the behaviour of the binding energy versus distance function (BEDF) of solids were reported years ago by Rose, Ferrante and Smith (RFS). In various phenomena, such as adhesion, chemisorption and bulk cohesion, it was possible to scale the binding energy and the interatomic distance so that data for various systems could be described by the same, “universal”, binding energy relation (UBER). At the 1995 Ringberg Workshop on Unary Data (Calphad 19 (1995) 538) it was recommended that the RFS approach should be considered as an alternative for correlating and predicting cohesive properties, as well as the parameters of the equation of state of solids (EOS). This possibility has been explored by us, using theoretical information on the energy versus volume relations at zero kelvin, that has been obtained in tight-binding linearized-muffin-tin-orbitals (TB-LMTO) calculations. The cohesive energy, equilibrium volume, bulk modulus and its pressure derivative (Be′) have been obtained for elements of the second row of the periodic table, viz., Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd and Ag, in the bcc, fcc and hcp structures. With this extensive database a critical test of the hypothesis of “universality” has been carried out. Moreover, the applicability of the RFS approach in predicting Be′ has been examined. The results for stable phases have been compared with experimental data. Finally, the structure dependence of Be′ has been discussed, which is a key issue in dealing with the EOS of non-stable structures of the elements.