Surface-Enhanced Raman Spectra of Thymine Calculated by DFT and ab Inition HF
CHEN Shan-jun1, 2, CHEN Yan1, ZHOU Xiu-wen2, LUO Bing-chi1, LI Xi-bo1, TANG Yong-jian1*, SUN Wei-guo2
1. Research Centre of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China 2. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
Abstract：In the present paper, B3LYP (Becke’s three-parameter hybrid method with the Lee, Yang, and Parr gradientcorrected correlation functional) and HF (Hartree-Fock) methods at 6-31+G**(C，H，N，O)/LANL2DZ(Ag) level were used to optimize molecular configurations of thymine. Base on the optimized structure, the normal Raman spectrum (NRS) of thymine and the surface-enhanced Raman spectrum (SERS) of thymine adsorbed on Ag and Ag2 were calculated, which were compared with the experimental values. The calculation results indicated that the result of the DFT for NRS was more approximate to the ever reported experimental date than those of HF results. A better conformity of SERS was found between the HF computed and the experimental results. At the end, detailed analysis of the Raman spectrum and more comprehensive assignments of the vibration mode for thymine were studied by the software of GaussView.
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