异核VMn氢化物稳定构型及金属间化学键  

VMn hydride stable configurations and intermetallic bond

作　　者：任桂明 谌晓洪 REN Gui-Ming;CHEN Xiao-Hong(Basic Department of Mathematics and Physics,Officers College of People＇s Armed Police Force,Chengdu 610213,China;School of Science,Xihua University,Chengdu 610039,China)

机构地区：[1]武警警官学院基础部,成都610213 [2]西华大学理学院,成都610039

出　　处：《四川大学学报（自然科学版）》2018年第6期1230-1238,共9页Journal of Sichuan University(Natural Science Edition)

摘　　要：用密度泛函DFT方法,相关泛函和交换泛函均采用PW91泛函,所有原子均采用DZP全电子极化基组,研究了VMnHx(x=1～5)系列分子的较低能量构型.讨论了VMnHx(x=1～5)团簇分子的基态分子结构、红外光谱特征、热力学稳定性及其金属间化学键.结果表明:VMnHx(x=1～5)基态构型所属点群及电子态分别为:VMnH(Cs,2 A′)、VMnH2(Cs,1 A′)、VMnH3(Cs,2 A″)、VMnH4(C3 v,3 A1)和VMnH5(C1,2 A).其最高占据轨道(HOMO)与最低空轨道(LUMO)间能隙值均大于30kcal·mol-1,其中最大为VMnH4(60.2kcal·mol-1),最小的是VMnH (34.6kcal·mol-1).平均原子化能随着氢原子个数的增加而单调增加.其电子亲和能最大都小于4kcal·mol-1,对电子的吸附能力也很弱.VMnH4的VMn间金属间化学键为单键,其余金属间化学键均为三键.The lower energy stable geometric configurations of VMnH x （ x =1~5） have been investigated by employing the hybrid density functional method （DFT） where the exchange-correlation functional in PW91 functional together with double-ζ polarization （DZP） basis sets are used. The properties of ground states also have been discussed. These properties include their ground state molecular stereo-structures and infrared spectral characters, thermodynamic stabilities and chemical bonds between metal atoms. The results show that： the point groups and their electronic states of these ground state molecules are VMnH（C s , ^2 A′ ）, VMnH 2 （C s , ^1 A′）, VMnH 3 （C s , ^2 A″）, VMnH 4 （C 3v , ^3 A 1 ） and VMnH 5 （C 1 , ^2 A）, respectively. Their energy gaps between the highest occupied orbital （HOMO） and the lowest empty orbital （LUMO） are all bigger than 30 kcal·mol^ -1 , the largest one is VMnH 4 with 60.2 kcal·mol ^-1 , and the lowest one is VMnH with 34.6 kcal·mol ^-1 . The average atomization energies of VMnH x （ x =1~5） increase monotonously as the number of hydrogen atoms increase. Their highest electron affinity is less than 4 kcal·mol ^-1 , meaning that their adsorption capacity for electrons is very weak. The intermetallic bond in ground VMnH 4 is a single bond, the other such bonds are triple bond.

关 键 词：过渡金属氢化物 密度泛函理论 基态构型 稳定性 金属间化学键 

分 类 号：O641[理学—物理化学]