二氧化碳的分子相图通过对TRAPPE模型的分子模拟
D González-Salgado1, M M Piñeiro2, C Vega3
1Departamento de Física Aplicada, Instituto de Física y Ciencias del Espacio, Universidad de Vigo, As Lagoas s/n 32004 Ourense, Spain.
The Journal of chemical physics
|August 14, 2025
概括
本研究评估了TraPPE分子力场,用于模拟二氧化碳 (CO2) 相位图. 虽然对某些过渡是准确的,但对于固相稳定性和密度预测需要改进.
科学领域:
- 物理化学 物理化学
- 计算材料科学科学 计算材料科学
- 热力学是一种热力学.
背景情况:
- 由于相位转移稳定性和过渡歇斯底里,对二氧化碳 (CO2) 相位图的实验性确定具有挑战性.
- 量子力学方法有助于区分分子和非分子CO2相.
- 从CO2-I到CO2-IV是分子相,而CO2-V和CO2-VI在高压和高温下是非分子相.
研究的目的:
- 评估TRAPPE分子力场在模拟CO2相位图的分子区域时的准确性.
- 通过使用经典模拟来验证TraPPE模型对已知的CO2阶段行为的预测.
主要方法:
- 经典的蒙特卡洛模拟.
- 分子动力学模拟.分子动力学模拟.
- 利用TRAPPE分子力场对二氧化碳进行检测.
主要成果:
- 该模型准确地预测了CO2-I,CO2-II,CO2-III和CO2-IV阶段的流体I过渡线和稳定区域.
- 确定的局限性包括低估了CO2-II和CO2-III的稳定性区域,以及在低于观察到的压力下预测的相位过渡.
- 固体相密度对于3GPa以下的CO2-I是很好的预测,但对于高压下所有固体来说都被低估了.
结论:
- TraPPE力场为CO2相图提供了合理的描述,特别是对于分子相.
- 需要对TRAPPE模型进行进一步的改进,以改善在高压下对固体相稳定性和密度的预测.
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