In this study, we perform a set of benchmark variational calculations for the ground state and for the 18 lowest bound excited ${}^{2}S$ and ${}^{2}P$ states of the boron atom. The nonrelativistic wave function of each state is generated in an independent calculation by expanding its wave function in terms of a large number ($10000–16000$) of all-electron explicitly correlated Gaussian functions (ECG). The Hamiltonian used in the calculations explicitly depends on the mass of the boron nucleus. The nonlinear parameters of the ECGs are extensively optimized with a procedure that employs the analytic energy gradient determined with respect to these parameters. These highly accurate nonrelativistic wave functions are used to compute the transition dipole moments and the corresponding oscillator strengths for all allowed transitions between the considered states. These quantities are reported for the transitions of the ${}^{10}\mathrm{B}$ and ${}^{11}\mathrm{B}$ isotopes, as well as for the boron atom with an infinite nuclear mass, ${}^{\infty }\mathrm{B}$, and used to evaluate the isotopic shifts of the oscillator strengths. The results generated in this work are considerably more accurate than the data obtained in the previous theoretical calculations.

中文翻译：

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中性硼中 P2−S2 跃迁的振荡器强度

在本研究中，我们对基态和 18 个最低激发态进行了一组基准变分计算${}^{2}S$和${}^2磷$硼原子的状态。每个状态的非相对论波函数是通过将其波函数展开为大量（$10000–16000$）的全电子显式相关高斯函数（ECG）。计算中使用的哈密顿量明确取决于硼核的质量。 ECG 的非线性参数通过采用根据这些参数确定的分析能量梯度的程序进行了广泛优化。这些高精度的非相对论波函数用于计算所考虑状态之间所有允许的跃迁的跃迁偶极矩和相应的振荡器强度。这些数量是为过渡而报告的${}^{10}\mathrm{乙}$和${}^{11}\mathrm{乙}$同位素，以及具有无限核质量的硼原子，${}^{\mathrm{无穷大}}\mathrm{乙}$，并用于评估振荡器强度的同位素位移。这项工作产生的结果比之前理论计算中获得的数据要准确得多。