COORDINATION-NUMBER 4 OR 6 FOR LITHIUM - THE CRYSTAL-STRUCTURE OF LITHIUM PERMANGANATE, LI[MNO4]

Waterless (Li[MnO4])-Li-7 was obtained by dehydration of (Li[MnO4].3D2O)-Li-7 at 60-degrees-C above P4O10 in vacuum as violet powder. The structure determination by neutron diffraction measurements via pulsed polychromatic neutron source [time-of-flight powder diffractometer; profile-R-value = 2.1%, Bragg-R-value = 7.4%] confirms the space group Cmcm with a = 551.402(8), b = 839.754(15), c = 635.911(10) pm (Z = 4); parameters see text. The crystal structure of Li[MnO4] corresponds to the CrVO4-type with coordination number 6 for lithium and 4 for manganese. The Madelung Part of Lattice Energie, MAPLE, the Effective Coordination Numbers, ECoN and the charge distribution were calculated and discussed.