MAGNETIC-PROPERTIES OF THE NEUTRAL MX CHAIN SYSTEMS

Both local density-functional (LDF) Stoner theory and spin-polarized L DF, each in conjunction with the scalar relativistic linear muffin-tin orbital technique, are used to study the magnetic properties of the n eutral halogen-bridged transition-metal linear chains, denoted by MX ( M=Ni or Pt, and X=Cl, Br, or I). Both approaches show that the Ni-base d compounds axe antiferomagnetic, whereas the Pt-based compounds are p aramagnetic. Besides these calculations, we have also studied the magn etism of the MX chain systems using the new density functional, which takes orbital polarization into account and uses a Hubbard interaction instead of the Stoner parameter. Despite the additional sophisticatio n of this approach, very similar results are obtained.