Results of of the detailed first-principle calculations of the structural, electronic, optical and elastic properties of the lithium amide LiNH2 crystals (hydrogen-storage material) are reported. Analysis of the density of states and band structure allowed for identifying peculiar features of the chemical bonds and electron density distribution. Difference in chemical bonding between the N-H and the Li-NH2 ions was demonstrated. For the first time, the anisotropy of the complex dielectric for this material was simulated. In addition, the first calculations of the anisotropic elastic constants for LiNH2 are reported. The origin of the principal band structure in relation to the optical constants dispersion is discussed. Following the obtained data, additional information about the anisotropy of the optical functions and elastic constants is given. (C) 2011 Elsevier B.V. All rights reserved.