NCO异构体结构与分析势能函数  

Structure and analytic potential energy function of NCO isomer

作　　者：李劲[1] 杨则金[2] 徐梅[3] 高涛[4] 杨向东[4] 

机构地区：[1]海南大学材料与化工学院海南优势资源化工材料应用技术教育部重点实验室,海口570228 [2]浙江工业大学理学院,杭州310023 [3]贵州师范大学物理与电子科学学院,贵阳550001 [4]四川大学原子与分子物理研究所,成都610065

出　　处：《原子与分子物理学报》2012年第2期247-254,共8页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10974139,10964002,11104247);海南省自然科学基金(110001);海南大学科研基金(kyqd1101);贵州省科学技术基金(黔科合J字[2009]2066号)

摘　　要：在B3LYP/6-31+G(d)水平上,对NCO分子的各种可能结构进行几何优化,得到了NCO及其异构体分子CNO和CON基态结构都是C_(∞v),电子态为X^2Ⅱ,NCO分子的平衡核间距R_(NC)=0.1230 nm,R_(CO)=0.1186 nm,离解能D_e=13.40 eV,并计算出谐振频率ω_1=1293.44 cm^(-1),ω_2(A′)=484.73 cm^(-1),ω_2(A″)=559.72 cm^(-1),ω_3=1988.41 cm^(-1),Renner-Teller参数ε=-0.1429,计算值与实验值吻合较好.在此基础上,应用多体项展式理论,单体项中首次引入开关函数,三体项以NCO,CNO基态结构与性质为依据,拟合给出了NCO分子的基态分析势能函数,其等值势能图准确再现了NCO,CNO分子基态结构与特征,并与优化结果完全一致.Density functional theory B3LYP method with the 631＋G（d） basis sets has been used to op timize the possible structures of the NCO,CNO and CON isomers. The results show that their ground states are all of C symmetries and in the X2II states. The equilibrium geometry, dissociation energy, harmonic frequencies, RennerTeller parameters and force constants of NCO and CNO molecules have been calculated. The analytic potential energy function of NCO molecule has been derived from the man ybody expansion theory. It is not just satisfied for the ground states of NCO and CNO molecules simul taneously, it also can be applied to the switch function in onebody term. The potential energy function can display the structure features and is consistent with the optimized results.

关 键 词：NCO异构体 多体项展式理论 开关函数 分析势能函数 

分 类 号：O562[理学—原子与分子物理]