物理学报2016，Vol.65Issue(16)：163101-1-163101-8,8.DOI:10.7498/aps.65.163101
SO分子最低两个电子态振-转谱的显关联多参考组态相互作用计算∗
Calculations on rovibrational sp ectra of two lowest electronic states in sulfur monoxide molecule by explicitly correlated approach
摘要
Abstract
Accurate spectroscopic constants and rovibrational level information are of great importance in molecular physics and astrophysical field. In this work, a new computational scheme is presented to further improve the accuracy of spectroscopic constants, and the two lowest electronic states of sulfur monoxide molecule are investigated as a typical case study. High-level ab initio calculations are carried out to compute the potential energy curves (PECs) of the lowest bound states, the ground triplet states X3Σ−g , and the first excited singlet states a1∆g of SO molecule. The explicitly correlated multi-reference configuration interaction method (MRCI-F12) and cc-pCVQZ-F12 basis set are adopted in the electronic structure computations. The Davidson correction is taken into account to eliminate the size-consistency error. The core-valence (CV) electron correlations of the n=2 shell of S atom and n=1 shell of O atom are estimated by the MRCI-F12 method, whereas only the 1 s orbital of S atom is excluded in the CV calculations. Moreover, we introduce the scalar relativistic effect into our study by utilizing the second-order Douglas-Kroll and Hess (DKH) one-electron integrals by the MRCI method through combining with the uncontracted cc-pCVQZ-F12 basis set. On the basis of the PECs of the SO dimer, the spectroscopic constants (Te, Re,ωe,ωeχe, Be,αe and De) of the two electronic states are determined by solving the one-dimensional nuclear rovibrational Schrödinger equations. Our spectroscopic constants are found to be in excellent agreement with previous experimental and theoretical values. Furthermore, the detailed information about the vibrational energy levels and rotation spectroscopic constants (Bν, Dν) of the two states is also presented with a deviation of 0.1%order of magnitude from the available experimental results. Our present computational work is valuable for future experimental studies on the rovibrational energy levels for the SO molecule and also indicates that the MRCI-F12 approach is cheap and accurate and expected to have wide applications in the PECs of other small molecular systems.关键词
SO/显关联多参考组态相互作用方法/光谱常数Key words
SO molecule/explicitly correlated multi-reference configuration interaction method (MRCI-F12)/spectroscopic constant引用本文复制引用
魏长立,梁桂颖,刘晓婷,颜培源,闫冰..SO分子最低两个电子态振-转谱的显关联多参考组态相互作用计算∗[J].物理学报,2016,65(16):163101-1-163101-8,8.基金项目
国家自然科学基金(批准号:11574114)和吉林省自然科学基金(批准号:20150101003JC)资助的课题.* Project supported by the National Natural Science Foundation of China (Grand No.11574114) and the Natural Science Foundation of Jilin Province, China(Grand No.20150101003JC) （批准号:11574114）
