Mg_2Ni氢化物电子结构的研究

Study on Electronic Structure of Mg_2NiH_4

利用电荷自洽离散变分Xα对Mg2Ni氢化物的电子结构进行研究,结果表明,在Mg2Ni氢化物中,H与Ni原子之间强烈的成键作用是导致Mg2Ni合金释放氢的温度比较高的原因.在A2B型贮氢合金中,因为氢原子更倾向于进入吸热型元素周围的晶格位置,所以吸热型元素在储氢合金中起到了增强对氢原子吸附力的作用.吸氢后,A2B型合金出现了A—B键受到减弱的现象,使得贮氢合金的性能降低了.

The electronic structure of Mg_2Ni hydride is studied by the S_(cc)-DV-X_α(Self-consistent-charge discrete variational X_α)method.It is found out that in the Mg_(2)NiH_(4), the strong bond which is formed by Ni atoms with H atoms results in Mg_(2)Ni alloy with high temperature when hydrogen atom is released.In A_(2)B type hydrogen storage alloys, hydrogen is apt to enter the crystal lattice place surrounding the endothermic elements.The functions of endothermic elements enforce the absorbability towards hydrogen. A_(2)B type hydrogen storage alloys all present the phenomenon that A-B bond is weaker after hydrogen atom is absorbed and result in the lower performance of alloy.