Ab initio study of H-2 desorption from magnesium hydride MgH2 cluster

作者：Tsuda M^*; Dino WA; Nakanishi H; Kasai H

来源：Journal of the Physical Society of Japan, 2004, 73(10): 2628-2630.

DOI：10.1143/JPSJ.73.2628

• hydrogen storage
• magnesium
• magnesium hydride
• desorption
• ionic bond
• density functional theory

In the present study, we investigate H-2 desorption from a magnesium hydride MgH2 cluster by performing total energy calculations based on the density functional theory (DFT). We calculate the potential energy surface (PES) for the H-2 desorption from a (MgH2)(5) cluster. According to the total atomic charges of the Mg and H atoms at the initial (MgH2)(5) cluster, the Mg-H bond is ionic-like. Because of this, the activation barrier for the H) desorption is considerably high (3.30 eV). Moreover, the structural relaxation for the system, allowing for only the two Mg atoms closest to the two desorbing H atoms, does not largely affect the potential energy of the system. The results indicate that the ionic-like Mg-H interaction is related to the thermodynamical stability of MgH2.

• 出版日期2004-10