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相关论文: Thermal Rate Coefficients for the Astrochemical Pr…

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The reaction between D$^+$ and H$_2$ plays an important role in astrochemistry at low temperatures and also serves as a prototype for simple ion-molecule reaction. Its ground $\tilde{X}~^1A^{\prime}$ state has a very small thermodynamic…

化学物理 · 物理学 2018-11-14 Somnath Bhowmick , Duncan Bossion , Yohann Scribano , Yury V. Suleimanov

The ring-polymer molecular dynamics (RPMD) was used to calculate the thermal rate coefficients of the two-channel roaming reaction H + MgH. Both reaction channels, tight and roaming, are explicitly considered. This is a pioneering attempt…

化学物理 · 物理学 2021-05-26 Hui Yang , Wenbin Fan , Junhua Fang , Jianing Song , Yongle Li

We have incorporated our experimentally derived thermal rate coefficients for C + H$_3^+$ forming CH$^+$ and CH$_2^+$ into a commonly used astrochemical model. We find that the Arrhenius-Kooij equation typically used in chemical models does…

天体物理仪器与方法 · 物理学 2016-11-23 S. Vissapragada , C. F. Buzard , K. A. Miller , A. P. O'Connor , N. de Ruette , X. Urbain , D. W. Savin

Ring polymer molecular dynamics (RPMD) is an accurate method for calculating thermal chemical reaction rates. It has recently been discovered that low-temperature calculations are strongly affected by the simulation parameters. Here, for…

化学物理 · 物理学 2021-04-28 Ivan S. Novikov , Yury V. Suleimanov , Alexander V. Shapeev

This Feature Article presents an overview of the current status of Ring Polymer Molecular Dynamics (RPMD) rate theory. We first analyze the RPMD approach and its connection to quantum transition-state theory. We then focus on its practical…

化学物理 · 物理学 2017-02-08 Yury V. Suleimanov , F. Javier Aoiz , Hua Guo

We combined Moment Tensor Potential (MTP) and Ring Polymer Molecular Dynamics (RPMD) for calculating the thermal rate constants of the OH + HBr system. We used the active learning (AL) algorithm for constructing a training set during RPMD.…

化学物理 · 物理学 2024-09-09 Ivan S. Novikov , Edgar M. Makarov , Alexander V. Shapeev , Yury V. Suleimanov

Rate coefficients have been measured for the reaction of CH radicals with formaldehyde, CH$_{2}$O, over the temperature range 31 - 133 K using a pulsed Laval nozzle apparatus combined with pulsed laser photolysis and laser induced…

太阳与恒星天体物理 · 物理学 2020-01-08 Niclas A. West , Tom J. Millar , Marie Van de Sande , Edward Rutter , Mark A. Blitz , Leen Decin , Dwayne E. Heard

We propose a methodology for fully automated calculation of thermal rate coefficients of gas phase chemical reactions, which is based on combining the ring polymer molecular dynamics (RPMD) with the machine-learning interatomic potentials…

化学物理 · 物理学 2018-12-26 Ivan S. Novikov , Yury V. Suleimanov , Alexander V. Shapeev

The accurate and efficient calculation of the rate coefficients of chemical reactions is a key issue in the research of chemical dynamics. In this work, by applying the dimension-free ultra-stable Cayley propagator, the thermal rate…

化学物理 · 物理学 2022-08-18 Xiongfei Gui , Wenbin Fan , Jiace Sun , Yongle Li

We apply Thermostatted Ring Polymer Molecular Dynamics (TRPMD), a recently-proposed approximate quantum dynamics method, to the computation of thermal reaction rates. Its short-time Transition-State Theory (TST) limit is identical to…

化学物理 · 物理学 2015-08-20 Timothy J. H. Hele , Yury V. Suleimanov

Our current understanding of interstellar carbon fractionation hinges on the interpretation of astrochemical kinetic models. Yet, the various reactions included carry large uncertainties in their (estimated) rate coefficients, notably those…

星系天体物理 · 物理学 2021-03-24 C. M. R. Rocha , H. Linnartz

We have investigated the chemistry of ${\rm C + H_3^+}$ forming CH$^+$, CH$_2^+$, and CH$_3^+$. These reactions are believed to be some of the key gas-phase astrochemical processes initiating the formation of organic molecules in molecular…

天体物理仪器与方法 · 物理学 2015-07-15 A. P. O'Connor , X. Urbain , J. Stützel , K. A. Miller , N. de Ruette , M. Garrido , D. W. Savin

The temperature dependence of the rate of the reaction CH_4+H \to CH_3+H_2 is studied using classical collision theory with a temperature-dependent effective potential derived from a path integral analysis. Analytical expressions are…

化学物理 · 物理学 2016-09-08 David Z. Goodson , Dustin W. Roelse , Wan-Ting Chiang , Steven M. Valone , J. D. Doll

The temperature dependence of the thermal rate constant for the reaction Cl($^2$P) + CH$_4$ $\rightarrow$ CH$_3$ + HCl is calculated using a Gaussian Process machine learning (ML) approach to train on and predict thermal rate constants over…

化学物理 · 物理学 2022-08-23 Paul L. Houston , Apurba Nandi , Joel M. Bowman

Ring polymer molecular dynamics (RPMD) has proven to be an accurate approach for calculating thermal rate coefficients of various chemical reactions. For wider application of this methodology, efficient ways to generate the underlying…

化学物理 · 物理学 2020-01-08 Ivan S. Novikov , Alexander V. Shapeev , Yury V. Suleimanov

Cross sections and rate coefficients for rovibronic excitation of the CH$^+$ ion by electron impact and dissociative recombination of CH$^+$ with electrons are evaluated using a theoretical approach combining an R-matrix method and…

星系天体物理 · 物理学 2025-11-25 Joshua Forer , Dávid Hvizdoš , Mehdi Ayouz , Chris H. Greene , Viatcheslav Kokoouline

The ring polymer molecular dynamics (RPMD) rate theory is an efficient and accurate method for estimating rate coefficients of chemical reactions affected by nuclear quantum effects. The commonly used RPMD treatment of gas-phase bimolecular…

化学物理 · 物理学 2025-04-03 Chen Li , Liang Zhang , Bin Jiang , Hua Guo

We revise the rates of reactions CH + S -> CS + H and C_2 + S -> CS + C, important CS formation routes in dark and diffuse warm gas. We performed ab initio calculations to characterize the main features of all the electronic states…

The experimental determination of the reaction rate coefficients for production and destruction of $\text{HCN}^+$ and $\text{HNC}^+$ in collisions with $\text{H}_2$ is presented. A variable temperature 22 pole radio frequency ion trap was…

星系天体物理 · 物理学 2023-06-08 Petr Dohnal , Pavol Jusko , Miguel Jiménez-Redondo , Paola Caselli

Observations of CH$^+$ are used to trace the physical properties of diffuse clouds, but this requires an accurate understanding of the underlying CH$^+$ chemistry. Until this work, the most uncertain reaction in that chemistry was…

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