  The stellar evolution code Modules for Experiments in Stellar Astrophysics
(MESA) is public and is widely used by the community. It includes the
possibility of taking several non-standard processes such as atomic diffusion
into account. Even if the effect of gravitational settling is considered a
standard ingredient in stellar modelling today, this is not the case for
radiative accelerations. The specific treatment of atomic diffusion along with
the radiative accelerations has never been compared with other stellar
evolution codes. Benchmarking these codes is important because improved
accuracy is required in order to analyse data from present and future space
missions, such as the \textit{Kepler}, Transiting Exoplanet Survey Satellite
(TESS), and PLAnetary Transits and Oscillations of stars (PLATO) missions.
  The aim of this paper is to compare MESA models including atomic diffusion
(with radiative accelerations) with models computed with the
Montreal/Montpellier stellar evolution code and with the Code d'Evolution
Stellaire Adaptatif et Modulaire (CESTAM). Additionally, we assess the impact
of some MESA options related to atomic diffusion.
  We calculated atomic diffusion, including radiative accelerations, following
the abundance profiles of 14 elements with MESA models. This was then compared
with 1.1 and 1.4~$M_{\odot}$ models computed with the Montreal/Montpellier and
CESTAM codes. Various tests of MESA options for atomic diffusion were also
carried out by varying only one of them at a time.
  We find that the abundance profiles of the considered elements in the MESA
models compare rather well with the models computed with the two other codes
when atomic diffusion options are carefully set. We also show that some options
in MESA are crucial for a proper treatment of atomic diffusion.
