摘要
采用基于密度泛函理论中的广义梯度近似,在考虑自旋多重度的情况下,对Yn NO(n=1—12)团簇进行了构型优化,以及稳定性和成键特性分析,结果表明:n=5,7,8,10时,NO吸附使相应的Yn团簇基态结构发生了明显变化,吸附后,所有尺寸中的N—O键长明显伸长,振动频率减弱,表明NO在Yn团簇表面发生的是解离性吸附,N—Y,O—Y键的共同作用使YnNO团簇具有很大的吸附能;特别是n=3,5,8时,N—O键断裂,吸附能值分别为9.92,9.24,9.82 eV.YnNO和Yn的二阶能量差分变化趋势表明,NO吸附对Yn团簇稳定性和成键特性均产生较大影响.N,O原子sp3轨道杂化时孤对电子的出现导致N—O键断裂,增强了N—Y和O—Y间的成键能力,使Y3NO,Y5NO,Y8NO团簇表现出了很好的稳定性.
The geometry structures, stabilities and chemical bonding properties of the Yn NO（n = 1–12） clusters are studied in the generalized gradient approximation based on the density functional theory with the consideration of spin multiplicities. The results show that NO adsorption changes the basic frameworks of the corresponding Yn clusters with n = 5, 7, 8, 10. The obvious elongation of N—O bond length and the attenuate vibrational frequency indicate that the adsorption of NO on Yn cluster can be regarded as the dissociative adsorption. The chemical bondings of N—Y and O—Y both simultaneously play an important role in enlarging the adsorption energy of Yn NO clusters. Specially, Y3 NO, Y5 NO, and Y8 NO have the giant adsorption energies（9.92, 9.24, and 9.82 eV） coupled with the break of the N—O bond. The calculated second-order energy differences suggest that the NO adsorption has influences on the stabilities and bonding properties of Yn clusters. The appearance of the couple electrons, arising from the sp3hybridization of N and O atom, not only leads to the fracture of N—O bond, but also enhances the ability to form N—Y bond and O—Y bond, which has important effects on the high stabilities of Y3 NO, Y5 NO, and Y8 NO clusters.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第24期141-147,共7页
Acta Physica Sinica
基金
山东省高等学校科技计划(批准号:J12LJ54)资助的课题~~
关键词
团簇
NO吸附
基态结构
稳定性
clusters
NO adsorption
basic structures
stabilities
