Y_2基态分子结构和光谱属性的DFT计算  

DFT Calculations on Molecule Structure and Spectroscopic Property of the Ground States of Y_2

作　　者：许永强[1] 彭伟成[2] 

机构地区：[1]赣南师范学院物理与电子信息学院,江西赣州341000 [2]赣南师范学院新闻与传播学院,江西赣州341000

出　　处：《赣南师范学院学报》2013年第6期25-28,共4页Journal of Gannan Teachers' College(Social Science(2))

基　　金：江西省教育厅科技计划项目(GJJ10240)

摘　　要：应用密度泛函理论(DFT)的B3LYP,B3PW91,BHLYP,BP86,B3P86,MPW1PW91,SVWN,PBE1PBE方法和有效核势(ECP)基组LANL2DZ,SBKJC VDZ,LANL2TZ,Stuttgart RSC 1997,CRENBL,ECP28MHF,ECP28MWB,ECP28MDF_VTZ,计算Y2分子基态的能量、平衡键长、谐振频率和离解能.比较各种不同方法和基组的计算结果,同时也与已有的实验和理论值进行比较.发现结果的精确性与计算的方法和采用的基组高度相关.对于X5Σ-u基态,用各种不同方法和基组得到的平衡键长范围为2.865 5到2.95,谐振频率范围为175.381 2到194.663 8 cm-1,离解能范围为1.439到3.237 eV.对于Y2基态结构和光谱属性的计算,从结果判断,BHLYP/ECP28MDF_VTZ方法应该是最适合的.The total energies, equilibrium bond lengths, harmonic vibrational frequencies, and dissociation energies of the X^5 ∑u^- ground state of Y2 dimer are calculated using density functional methods B3LYP, B3PW91, BHLYP, BP86, B3P86, MPW1PW91, SVWN, PBE1PBE and ECP Basis sets LANL2DZ, SBKJC VDZ, LANL2TZ, Stuttgart RSC 1997, CRENBL, ECP28MHF, ECP28MWB, ECP28MDF VTZ. A comparison is made of various density functional methods and different ECP basis sets. Results are also compared to other theoretical studies and to experimental values when available. The accuracy of the results is found to highly de-pendent upon the ealeultional methods and basis sets employed. For the X^5 ∑u^- ground state, different density function methods and ECP basis sets yields equilibrium bond lengths range from 2. 8655 to 2.95 A, the harmonic vibrational frequencies range is from 175. 381 2 to 194. 663 8 cm^-1 , the dissociation energies range is from 1. 439 to 3. 237 eV. Judging from these results, the BHLYP/ECP28MDF_VTZ method is excellent for the calculatons on molecule structure and speetroseopic property of the ground states of Y2.

关 键 词：Y2 密度泛函理论 有效核势(ECP)基组 

分 类 号：O561.1[理学—原子与分子物理]