沉重原子道在单点氧失活预测由实例理论与分支点奇点预测的重原子道
Imaad M Ansari1, Eric R Heller1,2, George Trenins1,3
1Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland.
Nature communications
|May 21, 2024
概括
一个新的理论解释了单片氧如何在水中衰变,揭示了量子道机制,比经典预测快27个数量级. 这一发现解决了化学物理学中长期存在的争议.
科学领域:
- 物理化学 物理化学
- 量子力学就是量子力学.
- 化学反应动力学 化学反应动力学
背景情况:
- 单个氧 (O2) 在溶剂中非辐射地衰变为其三重基态,这一过程涉及旋转交叉.
- 量子道在这个非adiabatic过程中的作用仍然是争论的主题.
- 现有的半古典实时理论面临的挑战是由于这种系统的流量相关函数的奇点.
研究的目的:
- 开发一个新的理论框架来分析由奇点主导的非adiabatic旋转交叉过程.
- 研究水中单点氧衰变的机制,包括量子效应.
- 为计算复杂系统中的反应速率提供一项第一原则的计算方法.
主要方法:
- 对具有分支点奇点的系统适用的新型实时理论的推导.
- 新理论与多参考电子结构计算的整合.
- 结合理论框架的应用,用于模拟水中的单点氧衰变.
主要成果:
- 提出了一种新反应机制,用于单片氧衰变在水中,明显比经典的途径更快.
- 量子道,特别是重原子道,在观察到的反应速率中起着至关重要的作用.
- 预测了一种大,温度依赖的动态同位素效应 (H2O/D2O ≈ 20),与实验观测结果相匹配.
结论:
- 开发的实时理论为研究非adiabatic量子道提供了一个强大的方法.
- 量子道对于理解水中单片氧的快速衰变至关重要.
- 理论预测与实验数据有很好的一致性,验证了新的方法.
相关概念视频
01:25Deactivation Processes: Jablonski Diagram
639
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
639
02:45The Quantum-Mechanical Model of an Atom
42.2K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
42.2K
03:18Nuclear Stability
18.8K
Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together...
To hold positively charged protons together...
18.8K
01:12Fermi Level Dynamics
243
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
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...
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...
243
02:13Bond Dissociation Energy and Activation Energy
8.8K
Bond energy is the energy required to break a bond homolytically. These values are usually expressed in units of kcal/mol or kJ/mol and are referred to as bond dissociation energies when given for specific bonds or average bond energies when indicated for a given type of bond over many compounds. Firstly, the bond dissociation energy for a single bond is weaker than that of a double bond, which in turn is weaker than that of a triple bond. Secondly, hydrogen forms relatively strong bonds with...
8.8K
02:35Molecular Orbital Theory I
32.0K
Overview of Molecular Orbital Theory
32.0K