The vibrational and rovibrational partition functions of diatomic molecules are considered in the regime of intermediate temperatures. The low temperatures are those at which the harmonic oscillator approximation is appropriate, and the high temperatures are those at which classical partition function (with Wigner–Kirkwood correction) is applicable. The complementarity of the harmonic oscillator and classical integration over the phase space approaches is investigated for the CO and H2+ molecules showing that those two approaches are complementary in the sense that they smoothly overlap.

中文翻译：

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关于谐波振荡器模型与经典 Wigner-Kirkwood 修正双原子分子分配函数的互补性

双原子分子的振动和振动分配函数被考虑在中间温度范围内。低温是谐振子近似适用的温度，高温是经典配分函数（Wigner-Kirkwood 校正）适用的温度。研究了 CO 和 H2+ 分子的谐振子和经典积分在相空间方法上的互补性，表明这两种方法在它们平滑重叠的意义上是互补的。