(1. 四川理工學(xué)院 材料與化學(xué)工程系，自貢 643000；
2. 重慶師范大學(xué) 功能材料實(shí)驗(yàn)室，重慶 400047)
摘 要: 利用電荷自洽離散變分Xα方法計(jì)算Al、Mg合金化對(duì)VH2電子結(jié)構(gòu)的影響。研究表明：在VH中加入金屬Al以后，H原子的凈電荷都減少，V原子的部分凈電荷增加部分凈電荷減少。V—H鍵間既有離子性相互作用，又有共價(jià)性相互作用；V—H鍵之間的相互作用減弱，氫容易被釋放出來(lái)，從而改善了吸放氫性能；Al和Mg合金化以后，V和H原子的凈電荷都減少，V—H鍵間的共價(jià)性相互作用增強(qiáng)；V—H鍵間的相互作用增加，有利于增加貯氫量，不利于改善吸放氫性能。
關(guān)鍵字: 氫化物VH2；合金化；離散變分Xα方法
（1. Department of Material and Chemical Engineering, Sichuan University of Science and Engineering,
Zigong 643000, China;
2. Functional Material Laboratory, Chongqing Normal University, Chongqing 400047, China）
Abstract: The effect of Mg and Al alloying on the electronic structure of VH2 was calculated by the self-consistent charge discrete variational Xα(SCC-DV-Xα) method. The calculated results indicate that when Al is added into VH2, the net charge of H decreases absolutely, on the other hand, the net charge of V decreases and increases partially. Both ionic and covalent interaction exist between V and H. With this interaction weakening, the hydrogen is easy to be released. So the property of absorbing and releasing of H is developed. When Mg alloys on VH2, the net charge of both H and V decreases and the covalent interaction of bond V-H strengthens. So it is advantage to raise the quantity of hydrogen storage, but it is disadvantage to improve the property of absorbing and releasing of hydrogen.
Key words: hydride VH2; alloying; self-consistent charge discrete variational Xα method
