论文部分内容阅读
在密度泛函理论的框架下,采用嵌入点电荷簇模型研究了O2在MgO(001)完整和缺陷表面上的吸附.用电荷自洽的方法确定了点电荷的值.计算结果表明,O2倾向吸附在低配位的角Mg2+端.并且发现,当O2为平躺吸附时,键长有较大的拉伸,将有利于O2的解离.同时,分别计算了使用裸簇和嵌入表观±2.0e点电荷簇模型时的吸附能,并与采用电荷自洽方法的计算值进行了比较.结果表明,电荷自洽方法更能有效反映簇周围的环境,得到的计算结果能够较好地与实验值吻合.最后,分别计算了不同吸附情况下O2的振动频率.
In the framework of density functional theory (DFT), the adsorption of O2 on the complete and defect MgO (001) surface has been studied by using the embedded-point charge-cluster model. The value of point charge has been determined by the self-consistent charge method. Adsorbed on the low coordination angle of Mg2 + side and found that when O2 is lying on the adsorption, the bond length has a larger stretch, will facilitate the dissociation of O2 at the same time, respectively, calculated using the naked cluster and embedded in the apparent ± 2.0e points charge-cluster model is proposed and compared with that calculated by the charge self-consistent method. The results show that the charge self-consistent method can effectively reflect the environment around the cluster, and the calculated results can be better Which is consistent with the experimental data.Finally, the vibration frequencies of O2 under different adsorption conditions were calculated respectively.