基数组和电子交换对应关系对低频振动和帕拉塞他多态的稳定性的影响
Huanyu Zhou1, Giuseppe Mallia1, Nicholas M Harrison1
1Department of Chemistry, Imperial College London, White City Campus, 80 Wood Lane, London W12 0BZ, United Kingdom.
精确的分子晶体模拟需要仔细选择计算参数. 使用三次-ζ基数组显著改善了对帕拉塞他多态的振动特性和热力学稳定性的预测.
科学领域:
- 计算化学是一种计算化学.
- 固态物理 固态物理
- 材料科学是一种材料科学.
背景情况:
- 分子晶体中的相变是由低频分子间振动驱动的.
- 密度函数理论 (DFT) 模拟通常会因为弱相互作用而对这些系统产生很大的错误.
- 准确预测晶体特性需要精确的计算方法.
研究的目的:
- 评估局部基础集和哈密尔顿数对分子晶体的DFT模拟的影响.
- 确定关键的计算参数,以准确预测振动特性和热力学稳定性.
- 提高DFT用于预测晶体结构和多态稳定性的可靠性.
主要方法:
- 研究了两种类型的甲醇多态,一个代表性的分子晶体.
- 将DFT计算与实验数据进行比较,包括低温几何,拉曼光谱和相位图.
- 系统地变化的基础集 (枢机性和扩散性) 和哈密尔顿元件.
主要成果:
- 基础组的选择,包括 cardinality (ζ) 和 diffuseness,显著影响振动特性和稳定性.
- 三倍-ζ def2-TZVP基础套件准确地捕获影响晶体稳定性的低频振动.
- 广泛使用的双-ζ基数组被发现是不充分的.
- 包括福克交易所在内显示了边际改善,特别是在三次-ζ基础集.
结论:
- 对分子晶体进行准确的DFT预测需要适当的基础集,特别是三次ζ.
- 这项工作解开了错误来源,提高了热力学建模中的DFT可预测性.
- 优化的计算参数导致更可靠的晶体结构预测和多态排名.
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