从头计算研究BP分子的势能曲线和光谱性质  

Ab initio calculation of the potential energy curves and spectroscopic properties of BP molecule

作　　者：王文宝[1,2] 于坤[1] 张晓美[1] 刘玉芳[1] 

机构地区：[1]河南师范大学物理与电子工程学院,新乡453007 [2]兴义民族师范学院物理与工程技术学院,兴义562400

出　　处：《物理学报》2014年第7期103-108,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11274096);河南省高校科技创新团队(批准号:13IRTSTHN016)资助的课题~~

摘　　要：利用高精度的量子化学从头计算MRCI+Q方法结合相关一致aug-cc-pVQZ基组计算了磷化硼分子X3Π,3Σ-,5Π和5Σ-态的势能曲线,计算所得的电子态在大键长位置处收敛于同一个离解极限B(2Pu)+P(4Su).为了得到更精确的结果,计算中首次纳入了旋轨耦合(SOC)效应,使得BP分子的4个Λ-S态分裂成为15个Ω态,其中3Π0+态被确定为基态.此外,SOC效应还使两个三重态X3Π和3Σ-分裂出的0+和1态的势能曲线产生了避免交叉,表明在当前的计算中考虑SOC效应是非常必要的.利用LEVEL8.0程序对计算所得的Λ-S态和Ω态的势能曲线进行拟合,得到了相应的光谱常数,通过与其他理论和实验工作进行比较,可知我们的结果更加精确、完整,可以为实验和理论方面进一步研究BP分子的光谱性质提供可靠的参考.A high-precision quantum chemistry ab initio multi-reference configuration interaction method with aug-cc-pVQZ basis sets has been used to calculate the four states of BP molecule. The four A-S states are X3Ⅱ,3∑-,5Ⅱand 5∑- which are correlated to the lowest dissociation limit of B（2Pu）＋p（4su）. Analysis of the electronic structures of A-S states shows that the A-S electronic states are essentially multi-configurational. We take the spin-orbit interaction into account for the first time so far as we know, which makes the four A-S states split into fifteen Ω states. 3Ⅱo＋ state is confirmed to be the ground Ω state. The SOC effect is essential for the BP molecule, which leads to the avoided crossings for 0＋ and 1 states from X3Ⅱ and 3E-. Based on the PECs of A-S and Ω states, the accurate spectroscopic constants are obtained by solving the radial SchrSdinger equation. The spectroscopic results may be conducive to further research on BP molecule in experiment and theory.

关 键 词：BP分子 MRCI+Q 势能曲线(PEC) 旋轨耦合(SOC) 

分 类 号：O561[理学—原子与分子物理]