钨酸铋钠晶体电子结构的理论模拟  

Electronic Structure of NaBi(WO_4)_2 Crystal Simulated by Density Functional Theory

作　　者：刘峰松[1] 顾牡[1] 张睿[1] 

机构地区：[1]同济大学物理系,上海200092

出　　处：《人工晶体学报》2005年第1期7-11,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No. 19774043);教育部高等学校优秀青年教师教学科研奖励计划(教人司(2002 )123 );高等学校博士学科点专项科研基金;上海市教育委员会重点学科研究项目;曙光计划(No. 02SG19);青年教师项目(No. 01QN18)资助

摘　　要：应用嵌入分子团簇的相对论密度泛函理论和离散变分 (DVM)计算程序,对Na、Bi两种不同占位状态钨酸铋钠晶体的电子结构进行了理论计算。经计算, (Bi4Na4W5O20 )6+团簇的禁带宽度为 4. 1eV,与实际晶体的禁带宽度相符;导带底主要是W5d轨道与Bi6p1 /2轨道,而价带顶则主要由O2p轨道组成;Bi轨道能级受Na、Bi离子占位因素影响较大。The electronic structure of double tungstate NaBi(WO4)2 (NBW) crystal was investigated by the relativistic self-consistent discrete variational (DVM) method with embedded cluster approach. The band gap of (Bi4Na4W5O20) 6+ cluster is 4.1 eV, which is corresponding to the experiment data. The simulation results show that the conduction band is mainly made up of W5dand Bi6p1/2 orbits, and the valence band is made up of O2p orbit. The results also show that the different configurations of Na and Bi ions in the NBW crystal will lead to the different energies of Bi6p1/2 orbit, which can affect the energy gap of the crystal.

关 键 词：晶体 电子结构 禁带宽度 分子团簇 占位 能级 密度泛函理论 钨酸 组成 轨道 

分 类 号：O561.1[理学—原子与分子物理] O641[理学—物理]