Density Functional Theory Study on [Ca(NH2)2]n (n=1∼5) Clusters

Possible geometrical structures and relative stabilities of [Ca(NH2)(2)](n) (n=1 similar to 5) clusters are studied by using the hybrid density functional theory (B3LYP) with 6-31G* basis sets. For the most stable isomers. electronic structures, vibrational properties. bonds properties, and ionization potentials are analyzed. The calculated results show that N-Ca and Ca-Ca bonds are favorable in the clusters, in which NH2 is bound to the framework of Ca atomic Clusters forming, ring-like structures. The bond lengths in [Ca(NH2)(2)](n) (n=1 similar to 5) Clusters are 0.225 similar to 0.257 nm for Ca-N, 0.312 similar to 0.354 nm for Ca-Ca, and 0.102 similar to 0.103 nm for N-H bonds. respectively. The bond angles of H-N-H are 102.9 degrees similar to 104.2 degrees. The population analysis suggests that the bonds between Ca and NH2 are of strong ionicity. The natural charges are -1.543e similar to 1.592e for N atoms. 1.657e similar to 1.720e for Ca atoms, and 0.349e similar to 0.367e for H atom, respectively. The comparative Study of structures and spectrum between Clusters and crystal shows that the structure of NH2 in clusters is consistent with that in crystal.