AI Article Synopsis
- A new four-dimensional treatment is introduced to explain the unusual centrifugal distortion in the open-shell methylene radical, considering both rotation and bending simultaneously.
- This method incorporates various coupling effects, including spin-rotation and hyperfine interactions, and successfully analyzes high-resolution data from 336 transitions with a low standard deviation.
- Compared to earlier analyses, this approach is more effective due to its use of a larger dataset and better data-to-parameter ratios, enabling the determination of the bending potential and key kinetic energy terms.
Article Abstract
A new treatment is presented to account for the extreme anomalous centrifugal distortion displayed by the open-shell methylene radical. This new treatment is based on a four-dimensional approach in which both the overall rotation and the large amplitude bending mode are treated simultaneously. It accounts for the spin-rotation and spin-spin fine couplings, assumed to depend on the large amplitude bending coordinate, as well as for the hyperfine coupling. The new treatment is tested analyzing the available high-resolution data. 336 transitions, involving the ground and first excited vibrational states of the bending mode, are reproduced with a unitless standard deviation of 1.3, using 42 molecular constants. Compared to a previous analysis [S. Brünken et al., J. Chem. Phys. 123, 164315 (2005)], the present analysis is more satisfactory as it accounts for a larger dataset and the ratio of the number of data to the number of varied constants is larger. The present theoretical treatment also allows us to retrieve the bending potential and the main kinetic energy term.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/5.0026162 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Structurally and electronically driven uniaxial negative thermal expansion in BaIrO.
Chem Commun (Camb)
January 2025
EaStCHEM, School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK.
Negative thermal expansion is known to exist in a range of structure types but is extremely rare in hexagonal perovskites. Here we demonstrate that BaIrO displays negative linear thermal expansion in the direction of its face-shared IrO trimers, and apparent zero volume thermal expansion below 100 K. We present evidence that this anomalous thermal expansion is driven by an unusual form of rigid body phonon behaviour governed by the effective trimer valence state and therefore has structural and electronic components to the underlying mechanism.
View Article and Find Full Text PDFElectride transition in liquid aluminum under high pressure and high temperature.
J Chem Phys
January 2025
Key Laboratory of Efficient Low-carbon Energy Conversion and Utilization of Jiangsu Provincial Higher Education Institutions, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, China.
Despite the conventional view of liquid aluminum (l-Al) as a simple metal governed by the free-electron model, it exhibits unique bonding characteristics. This study uncovers a gradual transition from free electron to electride behavior in l-Al at high pressure and temperature, forming a type of two-component liquid where atomic and electride states coexist. The proportion of electride increases with pressure and temperature until reaching saturation, leading to notable changes in the pair-correlation function and coordination number of l-Al at saturation pressure.
View Article and Find Full Text PDFNon-Hermitian Theory of Valley Excitons in Two-Dimensional Semiconductors.
Phys Rev Lett
December 2024
School of Physics and Electronics, Hunan University, Changsha 410082, China.
Electron-hole exchange interaction in two-dimensional transition metal dichalcogenides is extremely strong due to the dimension reduction, which promises valley-superposed excitonic states with linearly polarized optical emissions. However, strong circular polarization reflecting valley-polarized excitonic states is commonly observed in helicity-resolved optical experiments. Here, we present a non-Hermitian theory of valley excitons by incorporating optical pumping and intrinsic decay, which unveils an anomalous valley-polarized excitonic state with elliptically polarized optical emission.
View Article and Find Full Text PDFEnsemble habitat suitability model predicts Suaeda salsa distribution and resilience to extreme climate events.
J Environ Manage
January 2025
State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian, 116023, China. Electronic address:
Climate anomalies lead to an increased occurrence of extreme temperature and drought events in coastal wetlands, resulting in heightened survival pressure on salt marsh plants. It is imperative to anticipate the effects of these events on the habitat suitability and resilience of coastal salt marsh vegetation to inform restoration efforts and management strategies. Herein, an ensemble model was developed to evaluate the recovery of Suaeda Salsa in the two subsequent years following the anomalously high temperatures and decreased precipitation experienced during the summer of 2018, potentially leading to a decline in this species in the eastern coast of Liaohe Estuary wetland (Bohai Sea, China).
View Article and Find Full Text PDFAtmospheric rivers cause warm winters and extreme heat events.
Nature
December 2024
Yale University, Department of Earth and Planetary Sciences, New Haven, CT, USA.
Atmospheric rivers (ARs) are narrow regions of intense water vapour transport in the Earth's atmosphere. These transient phenomena carry water from the subtropics to the mid-latitudes and polar regions, making up the majority of polewards moisture transport and exerting control on the precipitation and water resources in many regions. In addition to transporting moisture, ARs also transport heat, but the impact of this transport on global near-surface air temperatures has not yet been characterized.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!