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采用密度泛函理论(DFT)中的B3LYP方法和BP86方法,O原子基于6-311+G(d,p)基组,Ga原子基于Stuttgart基组,对Ga_3O_2~-/0与Ga_4O_3~-/0团簇的各种可能构型进行了几何优化,预测了各团簇的最稳定结构,并研究了Ga_3O_2~-和Ga_4O_3~-最稳定结构的成键特性、振动特性和稳定性。对比B3LYP和BP86计算结果发现得到的异构体的结构和能量顺序相同,且阴离子的基态构型与中性分子的构型相接近,都是平面C_(2v)型,都存在由2个Ga原子和一个O原子形成的三中心二电子(3c-2e)桥键。两结构中处于端位的“Ga-O”键的Wiberg键级数值较大,分别为0.50、0.55;振动频率分别为713.92、832.76cm-1,在红外谱图上皆对应一明显的强振动峰,表明该“Ga-O”结构单元成键稳定,是决定团簇结构稳定的重要因素。计算得到是Ga_3O_2~-和Ga_4O_3~-基态结构的LUMO与HOMO的能量之差(分别为2.75、2.84eV),以及电子绝热剥离能(ADE)和电子垂直剥离能(VDE),都表明两基态结构具有较好的热力学稳定性。
By using the B3LYP method and the BP86 method in density functional theory (DFT), O atoms are based on the 6-311 + G (d, p) basis group and the Ga atoms are based on the Stuttgart basis set for Ga_3O_2 ~ - / 0 and Ga_4O_3 ~ - / 0 clusters were geometrically optimized, the most stable structures of each cluster were predicted, and the bonding properties, vibration characteristics and stability of the most stable structures Ga 3 O 2 - and Ga 4 O 3 ~ were studied. Comparing the results of B3LYP and BP86, it is found that the isomers obtained have the same structure and energy order, and the configurations of the ground states of the anions are close to that of the neutral molecules. Both of them are planar C_ (2v) A three-center di-electron (3c-2e) bridge formed by an atom and an O atom. The Wiberg bonds of the “Ga-O” bonds at the ends of the two structures are larger, which are 0.50 and 0.55, respectively. The vibrational frequencies are 713.92 and 832.76 cm -1, respectively. Strong vibration peak, indicating that the “Ga-O ” structural unit bonding stability, is an important factor in determining the stability of the cluster structure. The calculated energies of LUMO and HOMO (2.75 and 2.84 eV), as well as the ADE and VDE of Ga 3 O 2 - and Ga 4 O 3 - Structure has good thermodynamic stability.