  Accurate theoretical methods are needed to correctly describe adsorption on
solid surfaces or in porous materials. The random phase approximation with
singles corrections scheme (RPA) and the second order M{\o}ller-Plesset
perturbation theory (MP2) are two schemes which offer high accuracy at
affordable computational cost. However, there is little knowledge about their
applicability and reliability for different adsorbates and surfaces. Here we
calculate adsorption energies of seven different molecules in zeolite chabazite
to show that RPA with singles corrections is superior to MP2 not only in terms
of accuracy but also in terms of computer time. Therefore RPA with singles is
suitable scheme for obtaining highly accurate adsorption energies in porous
materials and similar systems.

Chemical Physics