Calculating weak decay rates under stellar conditions for studying presupernova evolution of massive stars is a challenging task. Here, we show the importance of odd-A nuclei for presupernova simulations. In order to calculate the required nuclear matrix elements, we apply the pn-QRPA model in a deformed basis. Nuclear deformation, thought to play an integral role in calculation of associated weak decay rates, is taken into account in our model. We calculate Gamow–Teller (GT) strength distributions, \(\beta ^-\) emission and positron capture rates for selected odd-A nuclei. Our model does not employ the Brink–Axel hypothesis as used in previous calculations of weak decay rates, and we perform a state-by-state microscopic calculation of GT strength distributions from all parent excited states. Our calculated \(\beta ^-\) decay rates are in good agreement with large-scale shell model calculations.

计算恒星条件下的弱衰变率以研究大质量恒星的超新星演化是一项艰巨的任务。在这里，我们显示了奇A原子核对超新星前模拟的重要性。为了计算所需的核矩阵元素，我们在变形的基础上应用pn-QRPA模型。在我们的模型中考虑了核形变，该形变被认为在相关的弱衰变率的计算中起着不可或缺的作用。我们为选定的奇A核计算了Gamow–Teller（GT）强度分布，\（\ beta ^-\）发射和正电子捕获率。我们的模型没有采用先前在弱衰变速率计算中使用的Brink-Axel假设，而是对所有父激发态的GT强度分布进行了逐状态微观计算。我们的计算\（\ beta ^-\）衰减率与大规模壳模型计算非常吻合。