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arXiv 2406.07448cond-mat.mtrl-sci
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键极化率模型在分子动力学模拟拉曼散射建模中的准确性与局限性

Accuracy and limitations of the bond polarizability model in modeling of Raman scattering from molecular dynamics simulations

Atanu Paul, Maya Rubenstein, Anthony Ruffino, Stefan Masiuk, Jonathan Spanier, Ilya Grinberg

AI总结:

本文系统评估了由DFT参数化的键极化率模型在分子和钙钛矿固体拉曼光谱建模中的准确性与局限性,发现其可再现整体峰位特征,但非相互作用键假设限制了定量精度,并在大幅偏离基态结构时导致定性错误。

摘要:

从分子动力学(MD)模拟计算拉曼散射需要准确建模系统电子极化率沿其MD轨迹的演化。对于大体系,这需要使用原子级模型来表示电子极化率对原子坐标的依赖关系。键极化率模型(BPM)是最简单的此类模型,已被用于分子体系拉曼光谱的建模,但尚未应用于固态体系。本文系统研究了由密度泛函理论(DFT)结果参数化的BPM在一系列简单分子(如CO2、SO2、H2S、H2O、NH3和CH4)、较复杂分子(CH2O、CH3OH、CH3CH2OH和噻吩)以及BaTiO3和CsPbBr3钙钛矿固体中的准确性与局限性。我们发现BPM能够可靠地再现拉曼光谱的整体特征,如峰位移动。然而,除高度对称体系外,非相互作用键的假设限制了BPM的定量准确性;对于存在大幅偏离基态结构的体系,这一假设还会导致极化率演化和拉曼光谱在定性上不准确。

英文摘要:

Calculation of Raman scattering from molecular dynamics (MD) simulations requires accurate modeling of the evolution of the electronic polarizability of the system along its MD trajectory. For large systems, this necessitates the use of atomistic models to represent the dependence of electronic polarizability on atomic coordinates. The bond polarizability model (BPM) is the simplest such model and has been used for modeling the Raman spectra of molecular systems but has not been applied to solid-state systems. Here, we systematically investigate the accuracy and limitations of the BPM parameterized from density functional theory (DFT) results for a series of simple molecules such as CO2, SO2, H2S, H2O, NH3, and CH4, the more complex CH2O, CH3OH and CH3CH2OH and thiophene molecules and the BaTiO3 and CsPbBr3 perovskite solids. We find that BPM can reliably reproduce the overall features of the Raman spectra such as shifts of peak positions. However, with the exception of highly symmetric systems, the assumption of non-interacting bonds limits the quantitative accuracy of the BPM; this assumption also leads to qualitatively inaccurate polarizability evolution and Raman spectra for systems where large deviations from the ground state structure are present.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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