仅使用ab initio数据进行DFT/MRCI哈密尔顿参数化:I. 价值激发状态激发状态
Teagan Shane Costain1, Victoria Ogden1, Simon P Neville2
1Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
一个新的量子化学8 (QE8) 哈密尔顿提升了电子激发能量的计算. 这种先进的方法结合了密度函数理论和多参考配置交互,为核心和值激发提供了更高的准确性.
科学领域:
- 量子化学 是一个量子化学.
- 计算化学计算化学
- 理论化学 理论化学
背景情况:
- 精确计算电子激发能量对于理解分子特性和反应性至关重要.
- 现有的方法,如密度函数理论和多参考配置交互 (DFT/MRCI),在描述各种电子激发方面存在局限性.
- 这些方法的参数化通常依赖于特定的数据集,可能会限制它们的一般适用性.
研究的目的:
- 开发和验证一个新的DFT/MRCI哈密尔顿式 (QE8) 参数化,使用基准ab initio垂直激发能量.
- 调查交换相关性 (XC) 功能选择对DFT/MRCI计算准确性的影响.
- 用新的哈密尔顿式来评估近似的DFT/MRCI方法 (p-DFT/MRCI和DFT/MRCI) 的性能.
主要方法:
- 使用 QUEST 数据库对初始垂直激发能量的新型 DFT/MRCI 哈密尔顿式 (QE8) 的开发.
- 选择了一个新的XC函数,QTP17,以更好地描述核心和价值激发.
- 对QE8哈密尔顿式与基准量子化学计算的验证.
主要成果:
- 对于广泛的电子激发,QE8哈密尔顿式的平均绝对误差为0.16 eV.
- QE8显著提高了对双激发状态的DFT/MRCI的准确性.
- 使用QE8的近似方法 (p-DFT/MRCI和DFT/MRCI(2) 显示与完整的DFT/MRCI方法的定量一致,平均差异为0.01 eV.
结论:
- 与以前的DFT/MRCI配方相比,新的QE8哈密尔顿式提供了更准确,更平衡的垂直激发能量的描述.
- 选择 XC 函数对于实现 DFT/MRCI 计算的高精度至关重要.
- 快速近似的DFT/MRCI方法在与准确的QE8哈密尔顿式参数化时是可靠的.
更多相关视频
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
08:22Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
相关概念视频
Valence Bond Theory and Hybridized Orbitals
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
Molecular Geometry and Dipole Moments
Electronic Structure of Atoms
An atom comprises protons and neutrons, which are contained inside the dense, central core called the nucleus, with electrons present around the nucleus. Taking into account the wave–particle duality of electrons and the uncertainty in position around the nucleus, quantum mechanics provides a more accurate model for the atomic structure. It describes atomic orbitals as the regions around the nucleus where electrons of discrete energy exist, characterized by four quantum...
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to...
Van der Waals Equation
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
Fermi Level Dynamics
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
