Local spin density functional investigations of a manganite with perovskite-type derived structures

The electronic and magnetic structures of the perovskite CaMnQ(3) are self- consistently calculated assuming two crystal structures at the same formula unit volume within the local spin density functional theory and the augmen ted spherical wave (ASW) method. From the comparisons of energy differences between the different magnetic states the ground state configuration is an insulator with G-type ordering. This result together with the magnitudes o f the magnetic moments are in agreement with experiment. The influence of m ixing between Mn and O is found spin dependent from the analysis of the cry stal orbital overlap population (COOP) which enable to describe the chemica l bond. The calculations underline a feature of a half metallic ferromagnet which could be connected with the colossal magnetoresistance (CMR) propert y of related compounds.