Study on geometrical structure and spectrum ofpolymerization borohydride (BH3)n(n=13)

Abstract

The possible geometrical structures of polymerization borohydride (BH3)n(n=13) are optimized in computation, based on different methods of B3P86、B3LYP,MP2,LSDA and by combining the Dunning relevant and consistent base group cc-PVTZ. The configuration geometric parameter, the electronic structure, the vibrational frequency and spectrum of the most stable structure are obtained, and the total energy (ET), binding energy (EBT), the average binding energy (Eav), the ionization potential (EIP), the energy crack (Eg), the Fermi level (EF) and so on are also given. The results indicate that the total energy is lowest and its value is close to the reported values from B3P86 method. The ground state of the three kinds of borohydride are all singlet states, the ir electronic states respectively are 1A',1A, and 1A. The stable geometry configuration of BH3 molecule is the planar triangle, B2H6 has a symmetrical ethylene type D2h spatial structure, and between H-B produces the hydrogen bridge type with three-center double electronic key, B3H9 has a C3spatial structure, also produces a hydrogen bridge type of three-center double electronic key, but the three hydrogen bridge types are isolated from each other. Finally the infrared and the Raman spectrum, the average binding energy, the ionization potential, the energy gap, Fermi level and so on are analyzed. B2H6 is shown to be the most stable molecule in (BH3)n(n=13), the H-B bridge bond key long is longer than the terminal lond, the infrared intensity of strongest peak is a maximal value.