环状碲团簇Te_n(n=3-12)拉曼光谱的密度泛函理论研究

DFT study on raman spectra of cyclic tellurium clusters Te_n(n=3-12)

采用密度泛函理论研究了气相环状碲团簇Ten(n=3-12)的拉曼光谱.使用B3LYP方法,四种Dunning相关一致性基组(包括三ζ函数cc-p VTZ-PP,aug-cc-p VTZ-PP,sdb-cc-p VTZ以及sdbaug-cc-p VTZ基组)进行了计算.以Te12为例,基组是否包含弥散函数(aug)所造成的最大拉曼活性值差异仅为5.57和5.844/amu,相应的振动波数差异仅为0.34和0.27 cm-1,因此弥散函数对环状碲团簇的拉曼计算是无关紧要的.以采取aug-cc-p VTZ-PP基组计算Te7为例,振动波数与文献已有值之差最小仅为0.16 cm-1,计算结果与文献已有值符合得很好.各团簇的拉曼光谱图表现出不同的谱线轮廓,可以作为环状碲团簇相互间区分鉴别的有力依据.

Theoretical results of density functional theory calculations on cyclic tellurium clusters Te n （ n=3-12 ） are presented .Raman spectra are computed in gas phase using the B 3 LYP functional with four Dunning ’ s correlation consistent basis sets （ triple-ζcc-pVTZ-PP, aug-cc-pVTZ-PP, sdb-cc-pVTZ and sdb-aug-cc-pVTZ）.For Te12 cluster, the relativistic effects from diffuse functions （ aug） on Raman activities and wavenumbers are 5.57 A°4/amu,5.84A°4/amu, 0.34 cm^-1 and 0.27 cm^-1 , respectively.Thus, the use of dif-fuse functions is almost insignificant for Raman calculations on cyclic tellurium clusters .For Te7 computed at aug-cc-pVTZ -PP level,the minimum deviation between calculated wavenumbers and pre -existing values is 0.16 cm^ -1 , the calculated wavenumbers values are in good agreement with the pre -existing data .The investiga-ted clusters exhibit different spectral profiles , which are of utility to distinguish cyclic tellurium clusters .