计算精确可靠的Rovibrational光谱数据的轴承分子
C Zachary Palmer1, Rebecca A Firth1, Ryan C Fortenberry1
1Department of Chemistry and Biochemistry, University of Mississippi, Oxford, Mississippi, USA.
Journal of computational chemistry
|December 23, 2024
概括
一种新的混合量子化学方法,F12-TcCR+TZ QFF,准确计算含分子的振动和旋转数据. 这一进步为大气和星际化学提供了关键的光谱参考数据,而实验数据很少.
科学领域:
- 量子化学 是一个量子化学.
- 频谱学是一种光谱学.
- 天体化学是天体化学.
背景情况:
- 含的分子在地球大气层和外星环境中发挥作用.
- 这些分子的实验识别数据有限.
- 现有的量子化学方法为化合物提供了不准确的反振光谱数据.
研究的目的:
- 开发和基准测试一种可靠的量子化学方法,用于计算含分子的振动基准数据.
- 为了解决这些物种当前计算方法的局限性.
- 为在各种化学环境中识别含分子提供准确的光谱数据.
主要方法:
- 基准测试十种不同的量子化学方法的准确性.
- 开发一种称为F12-TcCR+TZ QFF的混合方法.
- 结合CCSD(T) -F12b/cc-pCVTZ与CCSD(T) 的标量相对论修正以及CCSD(T) -F12b/cc-pVTZ的非和术语.
主要成果:
- 在经过测试的十种方法中,F12-TcCR+TZ QFF方法始终产生了最准确的结果.
- 这种混合方法与气相和Ar矩阵实验数据都显示出了很好的一致性.
- 这种方法成功地处理了粘合的非刚性性质.
结论:
- F12-TcCR+TZ QFF是一种高度准确和可靠的方法,用于计算含分子的振动频谱数据.
- 这种计算进步可以大大帮助识别和研究这些重要的化学物种.
- 该方法为化合物中非刚性结合所带来的挑战提供了可行的解决方案.
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
5.6K
08:53Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
Published on: October 2, 2017
29.8K
相关概念视频
01:29IR and UV–Vis Spectroscopy of Aldehydes and Ketones
5.2K
Infrared spectroscopy, also known as vibrational spectroscopy, is mainly used to determine the types of bonds and functional groups in molecules. In aldehydes and ketones, the carbonyl (C=O) bond shows an absorption around 1710 cm-1. The C=O bond vibration of an aldehyde occurs at lower frequencies than that of a ketone. In addition to the C=O absorption in an aldehyde, the aldehydic C–H bond also gives two peaks in the 2700–2800 cm-1 range. This absorption, coupled with the...
5.2K
01:15NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones
3.7K
In aldehydes, the hydrogen atom connected to the carbonyl carbon helps distinguish aldehydes from other carbonyl compounds using ¹H NMR spectroscopy. The closeness of aldehydic hydrogen to the electrophilic carbonyl carbon highly deshields the hydrogen atom causing its signal to appear around 10 ppm in the ¹H NMR spectra. α hydrogens split the aldehydic proton signal, which helps identify the number of α hydrogens in the molecule. For instance, one α hydrogen creates a...
3.7K
01:24IR Spectroscopy: Molecular Vibration Overview
1.9K
When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
1.9K
01:16UV–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
01:26Raman Spectroscopy Instrumentation: Overview
296
A conventional Raman spectrophotometer includes a laser source, a sample holding system, a wavelength selector, and a detector.
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
296
01:22Atomic Absorption Spectroscopy: Instrumentation
566
An atomic absorption spectrophotometer (AAS) comprises several components: a radiation source, an atomizer, a monochromator, and a detector. The radiation source can be a hollow-cathode lamp (HCL) or an electrodeless-discharge lamp (EDL), both of which provide a narrow emission line of the required wavelength. However, some instruments use continuum sources and high-resolution monochromators to achieve a narrow range of radiation.
The atomizer used in AAS can be either a flame atomizer or an...
The atomizer used in AAS can be either a flame atomizer or an...
566