Quasiharmonic approximation applied to LiBH4 and its decomposition products

The quasiharmonic approximation has been applied to the potential hydrogen storage material LiBH4 and its decomposition products. Whereas the lattice constants that minimize the DFT potential energy give good agreement with the experimentally observed values, minimizing the quasiharmonic free energy with respect to the lattice constants results in a significant overestimation. The enthalpy of dehydrogenation of LiBH4, including vibrational effects, is calculated to be 59 +/- 1 kJ/mol H-2 at 0 K, or 62.5 +/- 1.1 kJ/mol H-2 at 298 K.