测量器不变激发状态线性和二次响应属性在元概括梯度近似中
Robin Grotjahn1, Filipp Furche1
1Department of Chemistry, University of California, Irvine, 1102 Natural Sciences II, Irvine, California 92697-2025, United States.
Journal of chemical theory and computation
|July 3, 2023
概括
尺寸不变对于电子结构方法至关重要. 这项研究对激发状态属性实施了标量不变电流-元泛化梯度近似 (cMGGAs),显示了在预测分子属性方面提高准确性的潜力.
科学领域:
- 计算化学计算化学
- 量子化学 是一个量子化学.
- 材料科学 材料科学 材料科学
背景情况:
- 尺寸不变对于电子结构计算至关重要,特别是在时间依赖密度函数理论 (TDDFT) 中.
- 超泛化梯度近似 (MGGAs) 经常使用尺度变量的动能密度,阻碍了它们在TDDFT中的应用.
- 之前的研究表明,尺度不变函数能提高激发能量的精度.
研究的目的:
- 为激发状态属性实施测量不变电流元概括梯度近似 (cMGGAs).
- 将这些方法扩展到二次响应特性,包括超极化性和两光子吸收横截面.
- 将cMGGAs与MGGAs进行比较,用于预测两光子吸收横截面.
主要方法:
- 实现cMGGAs和混合cMGGAs的兴奋状态梯度和二极子时刻.
- 扩展到二次响应特性:动态超极化性和两光子吸收截面.
- 综合性基准研究比较MGGAs和cMGGAs的两光子吸收横截面.
主要成果:
- 在预测两光子吸收横截面方面,M06-2X功能性优于GGA混合PBE0.
- 标尺不变的实现显示了激发状态属性的边际平均改善,但在特定情况下有显著的影响.
- 尺度变量MGGA二次响应属性接近尺度不变性,但错误没有界限.
结论:
- 测距不变的cMGGAs对于TDDFT中的激发状态属性是从根本上可取的.
- 这些实现提供了最小的额外计算成本,并且对于一致的响应属性计算是必要的.
- 虽然基准研究显示了有限的平均改善,但尺寸不变的方法确保了理论一致性并避免了无限的错误.
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