The demand for clean energies grows rapidly, therefore, research into new materials to be used as hydrogen reservoirs are necessary. With this work we try to provide some understanding on complex hydrides. The compounds studied are of the type Li-X-H, where X are lighter elements in the periodic table. With the participation of these elements we can obtain a high gravimetric hydrogen density. We performed a systematic study on these materials. In this work we used different ab-initio codes. The predictive power of first principle calculations have shown their importance in determining properties of new materials not yet synthesized. The ab-initio calculations help to shorten development times of new materials such as those proposed in this paper. Additionally, new data on materials studied in the past and others designed in this work are shown here. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.