We survey the current situation regarding chemical modelling of the synthesis of molecules
in the interstellar medium. The present state of knowledge concerning the rate coefficients …

The interstellar medium (ISM) is far from empty; rather it contains large molecular clouds
consisting of dust and gas. It is in these clouds that new stars form possibly with habitable …

Context. Understanding grain-surface processes is crucial to interpreting the chemistry in
many regions of the interstellar medium. However, accurate surface chemistry models are …

Context. Water is a key molecule in star-and planet-forming regions. Recent water line
observations toward several low-mass protostars suggest low water gas fractional …

Numerical models of photodissociation regions (PDRs) are an essential tool to quantitatively
understand observations of massive star forming regions through simulations. Few mature …

New, unexpected and largely unexplored physical phenomena occur in systems cooled to
very low temperatures. The background temperature in the universe is approximately 2.7 K …

In this study, we demonstrate for the first time that the unified Monte Carlo (MC) approach
can be applied to model gas–grain chemistry in large reaction networks. Specifically, we …

For the first time, we report a unified microscopic–macroscopic Monte Carlo simulation of
gas-grain chemistry in cold interstellar clouds in which both the gas-phase and the grain …

Context. The presence of dust can strongly affect the chemical composition of the interstellar
medium. We model the chemistry in photodissociation regions (PDRs) using both gas-phase …

In the earliest phases of star-forming clouds, stable molecular species, such as CO, are
important coolants in the gas phase. Depletion of these molecules on dust surfaces affects …