Abstract
The structure of two polymorphs of manganese dioxide, λ-MnO2 and γ-MnO2 and the spinel oxide LiMn2O4 have been refined by Rietveld analysis of powder neutron diffraction data. λ-MnO2, Fd3m, a = 8.0639(3) Å, RBragg = 1.81%, γ-MnO2, Pnam, a = 9.3229(11) Å, b = 4.4533(7) Å, c = 2.8482(3) Å, RBragg = 1.34% and LiMn2O4, Fd3m, a = 8.2468(2) Å, RBragg = 2.33%.