Energy levels, wavefunction compositions and electric dipole transitions in neutral Ca
Energy levels, wavefunction compositions and electric dipole transitions in neutral Ca
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DOI：
10.1088/0953-4075/32/9/305
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发表时间：
1999-05
期刊：
影响因子：
--
通讯作者：
J. E. Hansen;C. Laughlin;H. Hart;G. Verbockhaven
中科院分区：
文献类型：
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作者：
J. E. Hansen;C. Laughlin;H. Hart;G. Verbockhaven
一个组态相互作用的方法，结合使用的B样条基组的模型势，包括单电子和双电子核心极化效应的基础上，计算长期的能量和波函数的中性钙。结果报告单重态和三重态束缚态，和一些准束缚态以上的最低电离限，角动量高达L = 4。与实验和其他理论结果的比较表明，该方法产生的中性钙迄今获得的最准确的能量值。波函数的组成，必要的标签的水平，和半经验的极化势的波函数的影响进行了讨论，是一些最近的鉴定双激发态。它表明，考虑到双电子核心极化的最低条款的能量在Ca显着的变化，一般由几百厘米-1，效果迅速下降的较高的束缚态。对于具有n7的Rydberg态，结果的准确性通常优于几cm-1。对于具有明显3d特征的系列成员（或扰动器），误差可达150 cm-1。的波函数被用来计算振子的强度和寿命的一些条款，这些与现有的测量进行比较。协议是好的，但指出需要改进的测量。
A configuration-interaction approach, based on the use of B-spline basis sets combined with a model potential including monoelectronic and dielectronic core polarization effects, is employed to calculate term energies and wavefunctions for neutral Ca. Results are reported for singlet and triplet bound states, and some quasi-bound states above the lowest ionization limit, with angular momentum up to L = 4. Comparison with experiment and with other theoretical results shows that this method yields the most accurate energy values for neutral Ca obtained to date. Wavefunction compositions, necessary for labelling the levels, and the effects of semi-empirical polarization potentials on the wavefunctions are discussed, as are some recent identifications of doubly-excited states. It is shown that taking into account dielectronic core polarization changes the energies of the lowest terms in Ca significantly, in general by a few hundred cm-1, the effect decreasing rapidly for the higher bound states. For Rydberg states with n7 the accuracy of the results is often better than a few cm-1. For series members (or perturbers) with a pronounced 3d character the error can reach 150 cm-1. The wavefunctions are used to calculate oscillator strengths and lifetimes for a number of terms and these are compared with existing measurements. The agreement is good but points to a need for improved measurements.