On the Relation between Relativity and Periodic Trends within a Triad of Transition Metals

Abstract

An anal. was made of the 1st-order relativistic correction H1 to the nonrelativistic Hamiltonian H0. The 1st-order term H1 contains, in addn. to the spin-orbit coupling contribution, relativistic corrections to the kinetic energy, the nucleus-electron attraction, and the electron-electron repulsion. The relativistic correction to the kinetic energy in mols. of heavy metals is responsible for a substantial stabilization in the bonds between the metal and atoms of other elements. The relativistic correction to the kinetic energy can contract the bond involving heavy metals by .gtoreq.1 .ANG.. Results are presented for calcns. on Cr2, Mo2, and W2 where the stability order is changed from Mo2 > W2 > Cr2 to W2 > Mo2 > Cr2 by relativity.