Local Disorder in Lithium Imide from density functional simulation and NMR Spectroscopy

Born–Oppenheimer molecular dynamics simulations in combination with calculations of 1H, 7Li, and 15N NMR chemical shifts are used to characterize lithium imide structures at different temperatures. Indications of the onset of local disorder in the lithium sublattice, leading eventually to superionicity, are recognized already at low temperature (100 K). Between 100 and 400 K, a new structure could be stabilized, which presents features that are intermediate between the previously reported Fm3m�and the Fd3m�structures. The disorder in the Li positions is associated with the reorientation of the NH bonds, which preferentially point toward Li-vacant sites. Clear signatures of such structural rearrangements are visible in the simulated NMR spectra, where smoother profiles are associated with a reduced amount of Li interstitials and a higher occupation probability of the antifluorite sites. DOI: https://doi.org/10.1021/jp300427 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-65302 Accepted Version Originally published at: Bonnet, M L; Iannuzzi, M; Sebastiani, D; Hutter, J (2012). Local disorder in lithium imide from density functional simulation and NMR spectroscopy. Journal of Physical Chemistry C, 116(35):18577-18583. DOI: https://doi.org/10.1021/jp300427 Local Disorder in Lithium Imide from density functional simulation and NMR Spectroscopy Marie-Laure Bonnet,[a] Marcella Iannuzzi,*[a] Daniel Sebastiani,[b] and Jürg Hutter[a] [a] Physikalisch-chemisches Institut, Universität Zürich Winterthurerstrasse 190, 8057 Zürich (Switzerland) Fax: (+41)44-635-6838 [b] Dahlem Center for Complex Quantum Systems Institute for Theoretical Physics, Freie Universität Berlin Arnimallee 14, 14195 Berlin (Germany) AUTHOR EMAIL ADDRESS [email protected] RECEIVED DATE (to be automatically inserted after your manuscript is accepted if required according to the journal that you are submitting your paper to)