中文摘要：

采用考虑Davidson修正的内收缩多参考组态相互作用方法和相关一致基aug—CC—pV5Z，在0．103—1．083nm的核间距内计算了SO＋离子b4∑-态的势能曲线．采用态相互作用方法和非收缩全电子aug．CC—pCVTZ基组、利用完全Breit—Pauli算符计算了旋轨耦合效应对光谱常数的影响．为提高势能曲线和旋轨耦合常数的计算精度，考虑了核价相关效应和相对论效应对势能曲线的影响．核价相关效应是使用CC—pCVTZ基组计算的；相对论效应是在-cc-pV5Z基组水平上使用三级Douglas．Kroll．Hess哈密顿算符计算的．利用得到的势能曲线，计算了各种情况下的光谱常数，并进行了详尽的分析和讨论．结果表明：在MRCI＋Q／aug—cc—pV5Z＋CV＋DK理论水平获得的光谱常数总体上最接近实验值．在MRCI＋Q／aug-cc-pV5Z＋CV＋DK理论水平，用全电子aug—cc—pCVTZ基组计算旋轨耦合修正时得到的旋轨耦合常数为1cm^-1．利用MRCI＋Q／aug-cc-pV5Z＋CV＋DK理论水平得到的势能曲线，通过求解核运动的振转Schr6dinger方程，计算了无转动SO＋离子b4∑-态前20个振动态的G（v），Bv和Dv等分子常数．其值与已有的实验结果一致．本文得到的光谱常数和分子常数达到了很高精度，能为进一步的光谱实验和理论研究提供可靠参考．文中的大部分光谱常数和分子常数均属首次报道．

英文摘要：

The potential energy curve （PEC） of b4∑- electronic state of the SO＊ cation is calculated using the internally contractea mui- tireference configuration interaction approach with the Davidson modification （MRCI＋Q） for internuclear separations from 0.103 to 1.083 nm. The basis set used is a correlation- consistent aug-cc-pV5Z basis set. The spin-orbit coupling effect on the spectroscopic parameters is taken into account by the state interaction approach with the full Breit-Pauli operator with all-electron basis set, aug- cc-pCVTZ. To improve the quality of PEC and spin-orbit coupling constant, core-valence correlation and relativistic corrections are included. Core-valence correlation correction is calculated using a cc-pCVTZ basis set. Relativistic corrections are included by the third-order Douglas-Kroll Hamiltonian approximation at the level of a cc-pVSZ basis set. At the MRCI＋Q/aug-cc-pV5Z＋CV＋DK level, the spin-orbit coupling constant of the SO＋ （b4∑-/2,3/2） is 1 cm-1 when the aug-cc-pCVTZ basis set is used for the spin- orbit coupling calculations The spectroscopic parameters are determined and compared with those reported in the literature. Excellent agreement is found between the present results and the measurements. The vibrational level G（v） inertial rotation constant Bv and centrifugal distortion constant Dvare predicted for each vibrational state of the b4∑-electronic state by solving the ro-vibrational Schr6dinger equation of nuclear motion using Numerov＇s method and those of the first 20 vibrational states are reported for the non- rotation SO＋ cation. Comparison with the measurements demonstrates that the present vibrational manifolds are both reliable and accurate. They should be good predictions for future experimental or theoretical research.