title: Studying the R-branch and the Q-branch emission spectral lines of diatomic molecules using improved analytical formula.
abstract: The difference converging method (DCM) used to predict the R-branch and the Q-branch high-lying rotational lines for diatomic systems is improved in this study. The key analytical formulae of the DCM method are modified by adding a higher order spectral term Hυ, and adding a physical converging criterion to improve the accuracy of predictions. Applications of the improved DCM method to the R-branch of the TiF molecule and the Q-branch of the (193)IrN molecule show that the accuracy of the R-branch and the Q-branch rotational lines is about one order of magnitude better than the results obtained using the previous formulae, which demonstrate the necessity of the added small term Hυ and the physical converging criterion. The DCM results are also shown to be better than the extrapolated rotational lines using the least-squares method.
authors.affiliation: College of Science, National University of Defense Technology, Changsha 410073, China; Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China; School of Science, Research Center for Advanced Computation, Xihua University, Chengdu 610039, China. Electronic address: swg@mail.xhu.edu.cn.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Sun
authors.affiliation: College of OptoElectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Science, Research Center for Advanced Computation, Xihua University, Chengdu 610039, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Fu
authors.affiliation: School of Science, Research Center for Advanced Computation, Xihua University, Chengdu 610039, China.
authors.forename: Qunchao
authors.initials: Q
authors.lastname: Fan
authors.affiliation: School of Science, Research Center for Advanced Computation, Xihua University, Chengdu 610039, China.
authors.forename: Huidong
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Science, Research Center for Advanced Computation, Xihua University, Chengdu 610039, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Feng
keywords: (193)IrN; Diatomic molecule; Difference method; Rovibrational transition; Spectrum; TiF