With the reformulation of the classical equations of collision-induced absorption, we present a method to perform the direct computation of the spectral density function. This way the absorption coefficient can be computed from classical molecular dynamics (MD) without the computationally demanding evaluation of the dipole autocorrelation function. In addition, we have developed an algorithm to extract the bound-to-bound dimer contribution to the MD simulated absorption. The method has been tested on the Ar–Xe rare gas system. Comparisons with quantum mechanical (QM) and conventional MD methods validate the approach. The obtained MD bound-to-bound spectra generally agree in shape and magnitude with QM results, including features stemming from rotations and vibrations of the Ar–Xe dimer.

通过对碰撞诱导吸收的经典方程的重新表述，我们提出了一种直接计算谱密度函数的方法。通过这种方式，可以从经典分子动力学 (MD) 计算吸收系数，而无需对偶极自相关函数进行计算要求的评估。此外，我们开发了一种算法来提取结合二聚体对 MD 模拟吸收的贡献。该方法已在 Ar-Xe 稀有气体系统上进行了测试。与量子力学 (QM) 和传统 MD 方法的比较验证了该方法。获得的 MD 结合光谱通常在形状和幅度上与 QM 结果一致，包括源自 Ar-Xe 二聚体的旋转和振动的特征。