A real-space method for the calculation of the orbital susceptibility of simple metals and transition metals

A real-space method for the calculation of the orbital susceptibility, chi 0 , of electrons in metals is developed. The authors express this quantity in terms of integrals over the spatial arguments of correlation functions and write chi 0 as the sum of the following three contributions: the Langevin diamagnetism, the Van Vleck paramagnetism and a term which yields the Landau diamagnetism in the limit of free electrons. The evaluation of chi 0 for the free-electron gas as a test case for the Al, Nb, V and Mo demonstrates its applicability to both simple and transition metals. In this work the Landau term for transition metals is calculated separately for the first time. They show that it provides an appreciable paramagnetic contribution in the cases of Nb and V.