密度泛函理论研究H2与Rhn（n=1—8）团簇的相互作用

采用密度泛函理论对H₂与Rh_n（n=1—8）团簇的相互作用进行了系统研究.结果表明, Rh_nH₂体系的最低能量结构是在Rh_n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Rh_n团簇的结构, 键长是影响Rh_n和Rh_nH₂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Rh_n的稳定性和化学活性，较小的吸附能表明H原子易从Rh_nH₂中解离出来.二阶能量差分表明4是Rh_nH₂和Rh_n团簇的幻数.关键词：nH₂和Rh_n团簇')" href="#">Rh_nH₂和Rh_n团簇平衡结构电子性质

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

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 Rh_n H_2 are generated with H atoms being adsorbed on the lowest energy structure of Rh_n clusters, and the lowest energy structures of Rh_n 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 H_2 is absorbed on the Rh_n clusters, the stability and chemical action of corresponding clusters are dramatically increased. The second order difference indicates 4 is magic number in Rh_n H_2 and Rh_n clusters. Among various possible adsorption sites, bridge site is energetically preferred for n≤5. The hollow site adsorption appears for n≥6.