GaxPy(x+y=8)及其阴离子团簇的结构与性质的DFT研究

用密度泛函理论方法对半导体二元微团簇GaxPy和GaxPy−(x+y=8)的几何结构、电子态、能量等进行了计算, 在B3LYP/6-311+G(2df)水平下完成结构优化和频率分析. 讨论了电荷诱导结构发生变化情况, 与中性团簇相比, 在阴离子团簇中, Ga—P键较P—P键有利于形成. 预测了未知Ga1P7−、Ga2P6−、Ga3P5−、Ga6P2−和Ga7P1−化合物的最稳定结构存在的可能性, 得出在GaxPy和GaxPy−(x+y=8)中, Ga4P4和Ga4P4−比较稳定. 给出了两种能差即绝热电子亲合势(ΔEAEA)和垂直电离能(ΔEVDE), 并与相关文献作比较. Ga4P4和Ga5P3的绝热电子亲合势与实验值相当吻合. 布居分析表明, 磷化镓团簇的成键属于混合键型.

Study on the Structure and Property of the Neutral GaxPy (x+y=8) and Anionic Gallium Phosphide Clusters Using DFT

Structure, electronic state, and energy of semiconductor binary micro-clusters, GaxPy and GaxPy-, having eight atoms have been computed using density functional theory (DFT) method. Structural optimization and frequency analysis are performed at the B3LYP/6-311+G(2df) level. The charged-induced structural changes of these anions have been discussed. The strong Ga-P bond is favored over the P-P bond in GaxPy- (x+y=8), in comparison with the corresponding neutral cluster. The calculations predict the existence of previously unknown isomers (i.e. Ga1P7-, Ga2P6-,Ga3P5-, Ga6P2- and Ga7P1-). Among different GaxPy and GaxPy- (x+y=8) clusters, Ga4P4 and Ga4P4- are more stable. Two types of energy separations are reported in this study, adiabatic electron affinities (△EAEA) and vertical detachment energies (△EVDE), wherever applicalde, and are compared with those described in other published data in the literature.Adiabatic electron affinities for Ga4P4 and Ga5P3 are in good agreement with those obtained in the experiments.Mulliken population analyses indicate that the bonding in GaP clusters is of a mixed type.