用差分收敛法研究NaLi分子部分电子态的完全振动能谱

基于双核分子振动能级的普遍表达式和差分收敛法(difference converging method, DCM), 利用微分思想将DCM应用于双核分子体系完全振动能谱的研究中. 应用DCM方法, 分别选用实验上获得的一组(10条)精确的振动能级, 对NaLi分子3¹Π, 4¹Π 和A¹Σ⁺电子态进行了研究, DCM的研究结果正确重复了已知数据并预测出了在实验上未能获得的包含高激发态在内的完全振动能谱数据, 同时计算得到了这3个电子态的振动光谱常数.

Full vibrational spectra of some electronic states of NaLi molecule using a difference converging method

For most diatomic electronic states, it is very difficult to obtain the accurate vibrational spectra of the highly-excited states directly by using the modern experimental techniques and quantum theories. Based on the general expression of diatomic molecular vibrational energy, the difference converging method (DCM) is used to give a new analytical expression in this paper. By using ten known vibrational energies, the full vibrational spectra, the vibrational spectroscopic constants of the highly-excited states, and the dissociation energy can be predicted for a diatomic electronic state. In this study, the full vibrational spectra of the electronic states 3¹Π, 4¹Π and A¹Σ⁺ of NaLi molecule are studied with the DCM and the new formula. Results show that all the vibrational levels given in the experiments can be reproduced with an error rate less than 0.02 percent in our study. In addition, By comparing with the reported experimental results, we find 26, 45 and 31 new vibrational levels for 3¹Π, 4¹Π and A¹Σ⁺ of NaLi molecule, respectively.