As the first example of a mixed metal amidoborane, Na2Mg(NH2BH3)(4) (DSMAB) contains both alkali and alkaline earth metals, has been demonstrated excellent properties of dehydrogenation. This is the first systematically study on its dehydrogenation mechanism. First, both the periodic and molecular structure have been studied. As for the kinetic study, the energy barrier of the possible dehydrogenation pathway is 57.99 kcal/mol, and the rate of the reaction is 6.0 x 10(-3) min(-1), which is consistent with the experiment result and provides evidence that oligomerization is the primary pathway based on the motion of Na+. (C) 2013 Elsevier B. V. All rights reserved.