Energetics of the Li Amide/Li Imide Hydrogen Storage Reaction
J. F Herbst, Louis Hector Jr
Physical Review B Condensed Matter 72, 125120 (2005)
A density functional theory investigation of the recently identiﬁed hydrogen storage reaction LiNH₂ + LiH ↔ Li₂NH + H₂ is described. The electronic structure and enthalpy of formation ΔH of each constituent are calculated in both the generalized gradient approximation (GGA) and the local density approximation (LDA). Zero point energies and ﬁnite temperature corrections to ΔH are derived via calculation of the vibrational spectra. We ﬁnd that the GGA provides much more favorable agreement with experiment than the LDA for the structural parameters and for ΔH(LiNH), ΔH(LiH), and the overall reaction enthalpy.