A one-to-one molar ratio of LiNH2 to MgH2 was ball milled and characterized to evaluate the proposed hydrogen storage reaction: LiNH2 + MgH2 double left right arrow LiMgN + 2H(2). The pressure-composition isotherm shows that less than 3.4 wt.% H-2 is released at a plateau pressure near 20atm at 210 degrees C. Furthermore, X-ray diffraction show that the products of the reaction include Li2Mg2(NH)(3) rather than LiMgN. Combined thermogravimetric and residual gas analyses reveal that large quantities of ammonia are released from the system. (C) 2007 Elsevier B.V. All rights reserved.