Gallium phosphides GamPn (m + n = 2-5) and their anions : Structures, electron affinities, and vibrational frequencies
Gallium phosphides GamPn (m + n = 2-5) and their anions : Structures, electron affinities, and vibrational frequencies
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磷化镓 GamPn (m n = 2-5) 及其阴离子：结构、电子亲和势和振动频率
DOI：
10.1002/qua.20779
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发表时间：
2006
影响因子：
2.2
通讯作者：
Hai
中科院分区：
文献类型：
--
作者：
Ling Guo;Hai
用四种杂化和纯密度泛函理论(DFT)方法研究了GamPn和GamP-n(m+n=2-5)团簇的几何构型、电子态和电子亲和能.在6-311+G(2df)单粒子基组的基础上进行了结构优化和频率分析。分别用每种DFT方法对几何形状进行了充分的优化。本文报道了三种能量分离：绝热电子亲和能(Ea A D)、垂直电子亲和能(Ea V E R T)和垂直分离能(Vde)。计算结果表明，单态结构比双态结构具有更高的对称性。预测分子结构的最好方法是BLYP，而其他方法通常低估了键长。在BP86和B3LYP理论水平下得到的最可靠绝热电子亲和能和垂直剥离能分别为2.22和2.10 eV(GaP)，2.51和2.46 eV(Ga2P)，1.86和1.94 eV(Ga2)，1.96和2.27 eV(Ga3)，1.76和1.99 eV(Ga3P)，1.79和2.14 eV(Ga2P2)，2.85和3.67 eV(Ga4)，Ga4 P分别为2.0 8和2.10 eV，Ga2 P3分别为2.90和3.17 eV，Ga3 P2分别为2.70和3.37 eV。Ga2P、Ga3P、Ga2P2、Ga4P、GaP4、Ga2P3、Ga3P2与实验值吻合较好，但GaP、Ga2P、GaP2、GaP3的预测值大于实验值。对于Gam-Pn系列的振动频率，B3LYP方法给出了较好的预测结果，与已有的实验值和理论值相比，平均误差仅为∼10 cm-1。其他三种方法高估或低估了振动频率，其中最差的是BLYP方法给出的预测。
Geometries, electronic states, and electron affinities of Ga m P n and Ga m P - n (m + n = 2-5) clusters have been examined using four hybrid and pure density functional theory (DFT) methods. Structural optimization and frequency analyses are performed with the basis of a 6-311+G(2df) one-particle basis set. The geometries are fully optimized with each DFT method independently. Three types of energy separations reported in this work are the adiabatic electron affinity (EA a d ), the vertical electron affinity (EA v e r t ), and the vertical detachment energy (VDE). The calculation results show that the singlet structures have higher symmetry than that of doublet structures. The best method for predicting molecular structures was found to be BLYP, while other methods generally underestimated bond lengths. The most reliable adiabatic electron affinities and vertical detachment energy, obtained at the BP86 and B3LYP level of theory, are predicted to be 2.22 and 2.10 eV (GaP), 2.51 and 2.46 eV (Ga 2 P), 1.86 and 1.94 eV (GaP 2 ), 1.96 and 2.27 eV (GaP 3 ), 1.76 and 1.99 eV (Ga 3 P), 1.79 and 2.14 eV (Ga 2 P 2 ), 2.85 and 3.67 eV (GaP 4 ), 2.08 and 2.10 eV (Ga 4 P), 2.90 and 3.17 eV (Ga 2 P 3 ), and 2.70 and 3.37 eV (Ga 3 P 2 ), respectively. Those for Ga 2 P, Ga 3 P, Ga 2 P 2 , Ga 4 P, GaP 4 , Ga 2 P 3 , and Ga 3 P 2 are in good agreement with experiment, but the predicted EA a d values for GaP, Ga 2 P, GaP 2 , and GaP 3 are larger than the available experimental values. For the vibrational frequencies of the Ga m P n series, the B3LYP method produces good predictions with the average error only ∼10 cm - 1 from available experimental and theoretical values. The other three methods overestimate or underestimate the vibrational frequencies, with the worst predictions given by the BLYP method.