TY - JOUR T1 - The Potential Energy Curves and Spectral Constants of $Si_2N$ AU - Han , Xiaoqin AU - Xiao , Xiajie JO - Journal of Atomic and Molecular Sciences VL - 3 SP - 172 EP - 178 PY - 2015 DA - 2015/06 SN - 6 DO - http://doi.org/10.4208/jams.071215.081615a UR - https://global-sci.org/intro/article_detail/jams/8234.html KW - harmonic frequency, force constants, potential energy function. AB -

The equilibrium geometries of $Si_2N$ have been calculated using different quantum chemistry calculation methods. Through a large number of test and research, the method QCISD/6-31G(2d,2p) is the most suitable for the calculation of $Si_2N$ by comparing the experimental equilibrium structure and harmonic frequency data. The force constants have also been calculated. Based on the general principles of microscopic reversibility, the dissociation limits has been deduced. The analytical potential energy function of $Si_2N$ has been obtained based on the many-body expansion theory. The potential surface graphs have been presented. It's found that there is a minimum value of 4.725eV at stable structure of the potential surface and a potential well of 1.7eV correspond to the linear asymmetric structures($^2\Pi).$ And the reaction of $SiN+Si → SiNSi$ based on the potential energy surface is discussed briefly, which is successfully used for describing molecular reaction dynamics.