价值电离和卫星转换的参考能量
Antoine Marie1, Pierre-François Loos1
1Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, Toulouse 31062, France.
Journal of chemical theory and computation
|May 22, 2024
概括
本研究引入了准确的计算方法,用于在原子和分子电离谱中建模"卫星"过渡. 这些方法为评估各种量子化学技术的性能提供了可靠的参考数据.
科学领域:
- 量子化学 是一个量子化学.
- 计算光谱学是一种计算光谱学.
- 理论原子和分子物理 理论原子和分子物理
背景情况:
- 电离可以导致同时发生电子激发,形成"卫星"或"摇"状态.
- 这些卫星过渡,在光谱中表现为较弱,更广泛的峰值,由于它们的高兴度,很难建模.
- 这些状态的准确建模对于理解复杂的电离过程至关重要.
研究的目的:
- 在小分子中计算卫星过渡和电离电位 (IP) 的高度精确的参考能量.
- 根据这些参考,评估各种量子化学方法的准确性,包括合集群 (CC) 和多体格林函数 (MBGF) 方法.
- 确定当前计算方法在描述卫星过渡时的局限性.
主要方法:
- 使用乱选择代 (CIPSI) 方法利用配置交互来获得完整的配置交互质量能量.
- 计算了42颗卫星的过渡能量和58个价值电离潜力 (IP).
- 评估了合集群 (CC2-CCSDTQ) 和多体格林函数 (GW,GF2,T矩阵) 近似的性能.
主要成果:
- 创建了一个准确的卫星过渡能量和小分子系统的IP的基准数据集.
- 与高质量的参考数据对比各种合集群方法的准确性.
- 分析了格林函数方法的性能,并讨论了它们对卫星过渡的局限性.
结论:
- 该研究提供了重要的参考数据,用于验证电离谱的理论模型.
- 突出了常用的计算方法在准确描述卫星过渡的挑战和局限性.
- 提供了关于改善对伴随电离的复杂电子激发现象的理论方法的见解.
相关概念视频
Ionization Energy
33.6K
The amount of energy required to remove the most loosely bound electron from a gaseous atom in its ground state is called its first ionization energy (IE1). The first ionization energy for an element, X, is the energy required to form a cation with 1+ charge:
33.6K
UV–Vis Spectroscopy: Molecular Electronic Transitions
1.4K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
1.4K
Atomic Radii and Effective Nuclear Charge
51.6K
The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number and distribution of electrons in their valence shells.
51.6K
π Electron Effects on Chemical Shift: Overview
1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
Molecular Spectroscopy: Absorption and Emission
2.3K
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
2.3K
Emission Spectra
52.1K
When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a range of energies, and thereby produce a continuous spectrum in which an unbroken series of wavelengths is present.
52.1K


