Theoretical investigation of zero field splitting parameters for Mn2+ centers in ammonium tartrate

Zero-field splitting (ZFS) parameters D and E for Mn2+ centers in ammonium tartrate single crystal are calculated with perturbation formulae using the superposition model. The theoretically calculated ZFS parameters for Mn2+ at site I and site II of ammonium ion are compared with the experimental values obtained by electron paramagnetic resonance (EPR) at room temperature. The superposition model gives the ZFS parameters similar to those from experiment. The energy band positions of optical absorption spectrum of Mn2+in ammonium tartrate are calculated using the CFA package and crystal field parameters from superposition model. These are in good agreement with experimental energy band positions.