密度泛函理论研究H_2与Rh_n(n=1—8)团簇的相互作用  

Density functional theory study of the interaction of H_2 with rhodium clusters

作　　者：葛桂贤[1] 曹海滨[1] 井群[1] 罗有华[2] 

机构地区：[1]石河子大学师范学院物理系,生态物理重点实验室,石河子832003 [2]华东理工大学理学院,上海200237

出　　处：《物理学报》2009年第12期8236-8242,共7页Acta Physica Sinica

基　　金：石河子大学高层次人才科研启动基金(批准号:RCZX200747)资助的课题~~

摘　　要：采用密度泛函理论对H2与Rhn(n=1—8)团簇的相互作用进行了系统研究.结果表明,RhnH2体系的最低能量结构是在Rhn团簇最低能量结构的基础上吸附H原子生长而成.吸附H原子没有改变Rhn团簇的结构,键长是影响Rhn和RhnH2磁矩的主要因素.从优化后的几何结构可以看出吸附后的H2发生断键,表明H2分子发生了解离性吸附.当n≤5,H原子的吸附以桥位为主,当n≥6时,H原子开始出现空位吸附.H原子的吸附提高了Rhn的稳定性和化学活性,较小的吸附能表明H原子易从RhnH2中解离出来.二阶能量差分表明4是RhnH2和Rhn团簇的幻数.The adsorption for H atoms on the Rh_n cluster has been systematically investigated by density functional theory. The result indicates that the lowest energy structures of RhnH2 are generated with H atoms being adsorbed on the lowest energy structure of Rhn clusters,and the lowest energy structures of Rhn clusters are not changed by adsorbing H atoms. The total magnetic moment is affected by average bond distance. The chemisorption of H atoms on Rh_n clusters belongs to dissociative adsorption. When H2 is absorbed on the Rhn clusters,the stability and chemical action of corresponding clusters are dramatically increased. The second order difference indicates 4 is magic number in RhnH2 and Rhn clusters. Among various possible adsorption sites,bridge site is energetically preferred for n≤5. The hollow site adsorption appears for n≥6.

关 键 词：RhnH2和Rhn团簇 平衡结构 电子性质 

分 类 号：O562[理学—原子与分子物理]