Sticking coefficients for atoms and molecules at the surfaces of interstellar dust grains

A fully quantum mechanical model of the particle–surface sticking process is developed, and calculations are performed for a variety of atoms, molecules and solids of relevance to the interstellar medium. The sticking coefficient is a sensitive function of the nature of the particle–surface interaction and the lattice phonon spectrum. Soft lattices and/or chemical adsorption ensure high sticking coefficients. For hard lattices and physical adsorption, sticking is unlikely to occur. The consequences for surface reactions in the interstellar medium are briefly discussed.