Coulomb Correlations and Magnetic Anisotropy in ordered $L1_0$ CoPt and   FePt alloys
  We present results of the magneto-crystalline anisotropy energy (MAE) calculations for chemically ordered $L1_0$ CoPt and FePt alloys taking into account the effects of strong electronic correlations and spin-orbit coupling. The local spin density + Hubbard U approximation (LSDA+U) is shown to provide a consistent picture of the magnetic ground state properties when intra-atomic Coulomb correlations are included for both 3$d$ and 5$d$ elements. Our results demonstrate significant and complex contribution of correlation effects to large MAE of these material. 
Alexander B. Shick, Oleg N. Mryasov (Institute of Physics ASCR,   Prague; Seagate Research, Pittsburgh)