Hartree band structure, Fermi surface, and nesting wave vector for paramagnetic chromium

In this paper it is demonstrated that it is possible to predict the wave vector of the spin-density wave in chromium without explict consideration of exchange and correlation effects. To do so the Fermi surface is obtained from a Hartree energy-band calculation and used to deduce the nesting wave vector. In this process the Fermi surface is presented using computer-graphic techniques which give clear views of the Fermi surface and its nesting portions. The Fermi surface and nesting wave vector are found to change dramatically as self-consistency is achieved in the energy-band calculation. For the self-consistent potential, agreement with the experimentally determined nesting wave vector is found to within about ten percent. It is concluded that the dominant exchange and correlation effects needed to establish the spin-density wave are implicitly included when the experimental lattice constant, lattice structure, and number of electrons per atom are introduced into the energy-band calculation.