First principles study of the structure, electronic state and stability of AlmAsn- anions

Structural and electronic properties of semiconductor binary microclusters AlmAsn- anions have been investigated using the B3LYP-DFT method in the ranges of m = 1-7 and n = 1, 2. Full structural optimization and frequency analysis are performed with the basis of 6-311+G(d). With Alm forming the base, adding As atom(s) in different positions would find the stable structures of AlmAsn- anions quickly and correctly. The charged-induced structural changes in these anions have been discussed. The strong As-As bond is also favored over Al-As bonds in the AlmAsn- anions in comparison with corresponding neutral cluster. Among different AlmAs− and AlmAs2- (m = 1-7) anions, both Al2As− and Al3As2- are predicted to be species with high stabilities and possible to be produced experimentally.