Crystalline materials have zero point energy (ZPE) associated with phonon vibrations. This ZPE not only significantly alters the energetics of reactions involving complex metal hydrides, but also alters the equilibrium structure of these materials as determined by first principles calculations. This paper focuses on the structural effect of ZPE in the potential hydrogen storage material LiBH4. (C) 2007 Elsevier B.V. All rights reserved.