POTENTIAL ENERGY CURVES AND CALCULATIONS OF SPECTROSCOPIC CONSTANTS FOR THE GROUND STATE OF AlC AND AlN
X. Liu1,2, Y. Yajun1, W. Xudong1, W. Yehui1, J. Meiping1, S. Chengxian1
1Changzhou University, Changzhou, Jiangsu, China
xianyunliu@gmail.com
2University of Tokyo, Meguro, Tokyo, Japan
Keywords: spectroscopic constants, potential energy surfaces, level, AlC, AlN
Abstract
The density functional theory method with B3LYP/6-311++G(df,pd), B3LYP/6-311++G(df,2pd), and B3LYP/6-311++G(3df,3pd) basis sets is used to compute the geometrics and single point energy of aluminum carbide (AlC) and aluminium nitride (AlN) in their ground state. The Level 8.0 program is used to calculate spectroscopic constants and fit the energy potential curves. The effect of a basis set on the spectroscopic constants is discussed. The results show that the calculated potential curve matches well with the Level 8.0 fitting curve, and the calculated values of spectroscopic constants become more reliable with the improvement of the quality of basis sets. The spectroscopic constants are in good agreement with the existing experimental and theoretical values. For the first time, the reliable anharmonicity constant data of AlC are reported, which agrees so well with the experimental value.
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