Quantum tunneling during interstellar surface-catalyzed formation of water: the reaction H + H$_2$O$_2$ $\rightarrow$ H$_2$O + OH

  title={Quantum tunneling during interstellar surface-catalyzed formation of water: the reaction H + H\$\_2\$O\$\_2\$ \$\rightarrow\$ H\$\_2\$O + OH},
  author={Thanja Lamberts and Pradipta Kumar Samanta and Andrea B. Kohn and Johann Kastner},
The final step of the water formation network on interstellar grain surfaces starting from the H + O2 route is the reaction between H and H2O2. This reaction is known to have a high activation energy and therefore at low temperatures it can only proceed via tunneling. To date, however, no rate constants are available at temperatures below 200 K. In this work, we use instanton theory to compute rate constants for the title reaction with and without isotopic substitutions down to temperatures of… 

Calculations of quantum tunnelling rates for muonium reactions with methane, ethane and propane.

Analysis of the results indicates that the kinetic isotope effect at this temperature is not significantly influenced by quantum tunnelling, and good agreement is found between the instanton predictions and new multiconfigurational time-dependent Hartree calculations for Mu + CH4 using the same potential-energy surface.

Efficient Production of S8 in Interstellar Ices: The Effects of Cosmic-Ray-driven Radiation Chemistry and Nondiffusive Bulk Reactions

In this work, we reexamine sulfur chemistry occurring on and in the ice mantles of interstellar dust grains, and report the effects of two new modifications to standard astrochemical models: namely,

Chemical Kinetics Approves the Occurrence of C (3P j) Reaction with H2O.

  • F. Keshavarz
  • Chemistry
    The journal of physical chemistry. A
  • 2019
This study provides new lines of evidence about the reaction through exploration of the reaction mechanism using the CCSD(T) method and solving the corresponding master equation by following two main approaches and approves the occurrence of the title reaction.

Extension of the HCOOH and CO2 solid-state reaction network during the CO freeze-out stage: inclusion of H2CO

Context. Formic acid (HCOOH) and carbon dioxide (CO2) are simple species that have been detected in the interstellar medium. The solid-state formation pathways of these species under experimental

Silicate-mediated interstellar water formation: A theoretical study.

Novel theoretical results concerning the formation of water adopting this mechanism on the crystalline Mg2SiO4 surface (a unequivocally identified interstellar silicate) are presented and Kinetic study results show that tunneling is crucial for the occurrence of the reactions and that formation of OH and H2O are the bottlenecks of the overall process.

A gas-phase primordial origin of O2 in comet 67P/Churyumov-Gerasimenko

Recent observations made by the Rosetta/ROSINA instrument have detected molecular oxygen in the coma of comet 67P/Churyumov-Gerasimenko with abundances at the 1–10 per cent level relative to H2O.

Ring-polymer instanton theory

Abstract Instanton theory provides a simple description of a quantum tunnelling process in terms of an optimal tunnelling pathway. The theory is rigorously based on quantum mechanics principles and

An accurate full-dimensional potential energy surface and quasiclassical trajectory dynamics of the H + H2O2 two-channel reaction.

A new full-dimensional potential energy surface (PES) of the H + H2O2 reaction, covering both H2 + HO2 and OH + H 2O product channels is reported, which implies a faithful representation of the discrete ab initio data over a large configuration space.



Barcia are acknowledged for their help and discussions in various stages of the project

  • 2007

MOLPRO, version 2015.1, a package of ab initio programs, 2015, see http://www.molpro.net

  • 2015