碱土金属Be、Mg、Ca掺杂磷团簇结构演变规律与光谱性质研究  

The study of growth patterns and spectra properties for alkaline earth Be,Mg,Ca doped P clusters

作　　者：王献伟[1] 龚森[1] 赵高峰[1] 

机构地区：[1]河南大学物理与电子学院,开封475004

出　　处：《原子与分子物理学报》2009年第3期452-460,共9页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10804027);河南省自然科学基金(2008A140002)

摘　　要：采用第一性原理在B3LYP/6-311G水平上对M_nP_m(n=1～2,m=1～10)(M=Be、Mg、Ca)团簇进行几何构型优化和频率分析,得到团簇各个尺寸的基态结构,结果表明,在m+n=5～6时锥体结构居多,相应的稳定性要高于同尺寸其他构型,m+n>6时,基态结构中出现四元环和五元环.裂化能和二阶能量差分计算结果表明,MP_m(m=1～10)团簇在m=2时同时获得局域的最大值,Be_2P_m(m=1～10)团簇幻数结构呈现规则的奇偶振荡.Be掺杂P团簇稳定性高于同尺寸的Mg、Ca掺杂,与Mg、Ca相比Be原子更易于与P原子结合.稳定结构团簇红外和拉曼光谱显示,高频段MP_2团簇红外和拉曼活性较强,Mg_2P_2,Ca_2P_2团簇红外谱主峰在高频段出现,与拉曼活性谱主峰相反.The ground state structures of M_n P_m (n = 1～2, m = 1 ～ 10) (M = Be, Mg, Ca) clusters were obtained with the structure optimization and frequency analysis at the B3LYP/6-311G level based on the density function theory. The calculated results indicate that the stabilities of M_nP_m clusters with m+n= 5,6 that adopt the cone structures are higher than the same size with other structures while the four or five ring are the ground state structures for the M_nP_m clusters With m+n>6. When m=2 the MP_m (m= 1～10) clusters simultaneously obtains the same local maximum value and the magic numbers of Be_2P_m (m=1～10) clusters exhibit the odd-even oscillation on the fragmentation energy and the second order difference. In comparison to Mg, Ca atoms,Be atom prefer to interact to P atoms of which its stability is higher. The MP_2 clusters exhibit the stronger activity of IR and Raman at the higher frequency size,and the main peak of the IR spectra also appear at the higher frequency size of the Mg_2P_2 and Ca_2P_2 clusters which is opposite to the main peak of Raman spectra through the investigation of the IR and Raman spectra for the magic numbers.

关 键 词：MnPm(n=1~2 m=1~10)团簇 稳定性 电子性质 红外和拉曼光谱 

分 类 号：O561[理学—原子与分子物理]