Modelling results obtained with MCPlas using the 4-species RKM (reaction kinetic model), option DDAn (improved drift-diffusion approximation) and boundary conditions (10), (11) and (14) from the manuscript. The data contain number densities of electrons and atomic argon ions, mean electron energy and number densities of metastable argon states in the stationary state of the DC glow discharge. Modelling was carried out for a constant voltage of 350 V, with a gap distance of 1 cm, a gas pressure of 1 Torr, and a gas temperature of 300 K.