Related papers: Molecular hydrogen formation on grain surfaces
Unraveling the adsorption mechanism and thermodynamics of O$_2$ and H$_2$O on uranium dioxide surfaces is critical for the nuclear fuel storage and uranium corrosion. Based on the first-principles DFT+U-D3 calculations, we carefully test…
We have used diffusion Monte Carlo (DMC) simulations to calculate the energy barrier for H$_2$ dissociation on the Mg(0001) surface. The calculations employ pseudopotentials and systematically improvable B-spline basis sets to expand the…
Molecular clouds typically consist of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as…
The molecular evolution that occurs in collapsing prestellar cores is investigated. To model the dynamics, we adopt the Larson-Penston (L-P) solution and analogues with slower rates of collapse. For the chemistry, we utilize the new…
Motivated by recent observations of deuterated molecules in the interstellar medium, we examine the production of HD and D$_2$ molecules on dust grain surfaces. A mechanism for the enhanced production of these deuterated molecules is…
We present P-GADGET3-K, an updated version of GADGET3, that incorporates the chemistry package KROME. P-GADGET3-K follows the hydrodynamical and chemical evolution of cosmic structures, incorporating the chemistry and cooling of H$_2$ and…
The recent unexpected detection of terrestrial complex organic molecules in the cold (~ 10 K) gas has cast doubts on the commonly accepted formation mechanisms of these species. Standard gas-phase mechanisms are inefficient and tend to…
Formamide has a key role in prebiotic chemistry as it is the simplest molecule containing the four most important atoms from a biological point of view: hydrogen, carbon, nitrogen and oxygen. Due to its importance, the formation of this…
There is accumulating evidence for the presence of complex molecules, including carbon-bearing and organic molecules, in the interstellar medium. Much of this evidence comes to us from studies of chemical composition, photo- and…
We use far-UV absorption spectra obtained with FUSE towards three late B stars to study the formation and excitation of H2 in the diffuse ISM. The data interpretation relies on a model of the chemical and thermal balance in…
The formation of interstellar water has been commonly accepted to occur on the surfaces of icy dust grains in dark molecular clouds at low temperatures (10-20 K), involving hydrogenation reactions of oxygen allotropes. As a result of the…
Adsorption of $O_{2}$ molecule on Al surface has been a long standing puzzle for the first principles calculation. We have studied the adsorption of $O_{2}$ molecule on the Al(111) surface using hybrid functionals. In contrast to the…
We show that the formation of the wetting layer and the experimentally observed continuous shift of the H2O-OH balance towards molecular water at increasing coverage on a TiO2(110) surface can be rationalized on a molecular level. The…
There has always been a great deal of interest in the formation of H2 as well as in the binding energy released upon its formation on the surface of dust grains. The present work aims at collecting experimental evidence for how the bond…
Understanding how the $\mathrm{H}_2$ molecule is formed under the chemical conditions of the interstellar media (ISM) is critical to the whole chemistry of it. Formation of $\mathrm{H}_2$ in the ISM requires a third body acting as a…
It is shown that mechanical alignment of grains can be efficient for grains rotating suprathermally, i.e. with kinetic energy substantially exceeding $k$ (the Boltzmann constant) over any temperature in the system. The paper studies…
Context. In dense clouds, hydrogenation reactions on icy dust grains are key in the formation of molecules, like formaldehyde, methanol, and complex organic molecules (COMs). These species form through the sequential hydrogenation of CO…
The catalytic role of dust grain surfaces in the thermal reaction CO2 + 2NH3 $\rightarrow$ NH4+NH2COO was recently demonstrated by our group. The rate coefficients for the reaction at 80 K on the surface of nanometre-sized carbon and…
The phase diagram of the first layer of H$_2$ adsorbed on top of a single graphene sheet has been calculated by means of a series of diffusion Monte Carlo (DMC) simulations. We have found that, as in the case of $^4$He, the ground state of…
Because H2 formation on dust grain surfaces completely dominates gas-phase H2 formation in local molecular clouds, it is often assumed that gas-phase formation is never important. In fact, it is the dominant mechanism in a number of cases.…