AI 中文总结
研究分子振动手性，引入原子间螺旋度赝标量作为补充度量，与固定部分电荷近似下的振动圆二色性强度相关，对扭曲乙烷模型等小分子效果良好，支持基于响应的度量表征振动手性，指出基于固定部分电荷的估计对实际分子振动圆二色性响应预测较差。
AI 中文摘要
近期对各种物理现象中手性声子及其在手性诱导自旋选择性效应中假设作用的关注，促使进一步研究分子振动的手性。传统上分子手性用结构性质量化，近期工作突出了动力学响应性质作为手性度量的作用。本文研究原子间螺旋度赝标量作为振动手性的补充度量，它与固定部分电荷近似下的振动圆二色性强度相关。该赝标量具有平移和旋转不变性，能区分对映体，且不依赖预定义对称轴。对扭曲乙烷模型和几个小分子，此赝标量与基于连续手性度量的结构描述符相关性良好。结果支持基于响应的度量作为振动手性的有物理意义且实用的表征。重要的是，基于固定部分电荷的振动圆二色性估计虽能量化振动手性，但因受分子电子响应影响，对实际分子振动圆二色性响应预测较差。
英文摘要
The recent interest in chiral phonons in a variety of physical phenomena and their hypothesized role in the chiral-induced spin selectivity effect [Phys. Rev. Research, 5, L022039 (2023)] call for further investigation into the chirality of molecular vibrations. Although molecular chirality has conventionally been quantified using structural properties, recent work has highlighted the role of dynamical response properties as chirality metrics. In this work, we examine an inter-atom helicity pseudoscalar as a complementary measure of vibrational chirality, associated with the vibrational circular dichroism (VCD) intensity in the fixed partial charge (FPC) approximation. This pseudoscalar is translationally and rotationally invariant, can distinguish between opposite enantiomers, and unlike an atomic pseudoscalar measure considered in our earlier work [Phys. Rev. Lett., 133, 268001 (2024)] does not rely on a predefined symmetry axis. For a twisted ethane model as well as several small molecules, this pseudoscalar correlates well with structural descriptors based on the continuous chirality measure. Overall, our results support response-based metrics as a physically meaningful and practically useful characterization of vibrational chirality. Importantly, while the FPC-based VCD estimate provides a useful quantifier of vibrational chirality, we show that it is a rather poor predictor of the actual molecular VCD response because the latter is strongly influenced by the (vibrational configuration-dependent) molecular electronic response.
