Band Structure of the Non—Oxide Perovskite MgCNi3

Using the self-consistent full-potential linearized augmented plane wave method,we carry out the electronic structure calculations of MgCNi3 in the local spin density approximation(LSDA) of the density-functional theory.The LSDA solution is metal.The magnetic moment on the Ni ion is only 0.014uB.There is a peak in the density of state just below the Fermi energy(Ef),which can be strongly correlated with various instabilities.After including the strong electron-electron correlation effects on the Ni 3d state by the on-site Coulomb interaction correction,the density of state is greatly redistributed.and the peak just below Ef disappears.The magnetic moment on the Ni ion becomes 0.66uB.Both LSDA and LSDA U have shown that the electroic states near the Fermi surface are dominated by the 3d orbital of Ni.