Related papers: Formation of molecular oxygen in ultracold O + OH …
We report quantum dynamics calculations of the O + OH -> H + O2 reaction on two different representations of the electronic ground state potential energy surface (PES) using a time-independent quantum formalism based on hyperspherical…
The reaction between atomic oxygen and molecular hydrogen is an important one in astrochemistry as it regulates the abundance of the hydroxyl radical and serves to open the chemistry of oxygen in diverse astronomical environments. However,…
Collision cross sections and rate constants between two ground- state oxygen molecules are investigated theoretically at translational energies below $\sim 1$K and in zero magnetic field. We present calculations for elastic and spin-…
OH is a cornerstone molecule in the chemistry of interstellar and circumstellar media and is ubiquitously detected in warm gas thanks to its infrared rotational lines. However, the excitation processes of OH remain poorly characterized. We…
It has recently become possible to form molecules in ultracold gases of trapped alkali metal atoms. Once formed, the molecules may undergo elastic, inelastic and reactive collisions. Inelastic and reactive collisions are particularly…
We have computed ab inito cross sections for cold collisions of Rb atoms with OH radicals. We predict collision rate constants of order 10^{-11} cm^3/s at temperatures in the range 10-100 mK at which molecules have already been produced…
Our knowledge about the "cold" Universe often relies on molecular spectra. A general property of such spectra is that the energy level populations are rarely at local thermodynamic equilibrium. Solving the radiative transfer thus requires…
A close coupling quantum-mechanical calculation is performed for rotational energy transfer in a HD+HD collision at very low energy, down to the ultracold temperatures: $T \sim 10^{-8}$ K. A global six-dimensional H$_2$-H$_2$ potential…
The mobility of O atoms at very low temperatures is not generally taken into account, despite O diffusion would add to a series of processes leading to the observed rich molecular diversity in space. We present a study of the mobility and…
Quantum scattering calculations are reported for the H+HCl(v,j=0) and H+DCl(v,j=0) collisions for vibrational levels v=0-2 of the diatoms. Calculations were performed for incident kinetic energies in the range 10-7 to 10-1 eV, for total…
Ultracold collisions between spin-polarized Na atoms and vibrationally excited Na_2 molecules are investigated theoretically, using both an inelastic formalism (neglecting atom exchange channels) and a reactive formalism (including atom…
Ultracold collisions of polar OH molecules are considered in the presence of an electrostatic field. The field exerts a strong influence on both elastic and state-changing inelastic collision rate constants, leading to clear experimental…
The formation of CO2 in quiescent regions of molecular clouds is not yet fully understood, despite CO2 having an abundance of around 10-34 % H2O. We present a study of the formation of CO2 via the non-energetic route CO + OH on non-porous…
Absorbing UV radiation, ozone protects life on Earth and plays a fundamental role in Earth's temperature balance. The formation of ozone occurs through the ternary recombination reaction: O$_2$+O+M $\rightarrow$ O$_3$+M, where M can be…
Trapping of atoms and molecules in electrostatic, magnetic and optical traps has enabled studying atomic and molecular interactions on a timescale of many seconds, allowing observations of ultra-cold collisions and reactions. Here we report…
OH radicals play a key role as an intermediate in the water formation chemistry of the interstellar medium. For example the reaction of OH radicals with H$_2$ molecules is among the final steps in the astrochemical reaction network starting…
We consider the prospect of using ultracold hydrogen atoms for sympathetic cooling of fluorine atoms to microkelvin temperatures. We carry out quantum-mechanical calculations on collisions between cold F and H atoms in magnetically…
Scattering and ionizing cross sections and rates are calculated for ultracold collisions between metastable helium atoms using a fully quantum-mechanical close-coupled formalism. Homonuclear collisions of the bosonic ${}^{4}$He$^{*}…
A statistical-type model is developed to describe the ion production and electron emission in collisions of (molecular) ions with atoms. The model is based on the Boltzmann population of the bound electronic energy levels of the quasi…
Collisions between cold molecules are essential for studying fundamental aspects of quantum chemistry, and may enable formation of quantum degenerate molecular matter by evaporative cooling. However, collisions between trapped, naturally…