The submodel PSC of the ECHAM5/MESSy Atmospheric Chemistry model (EMAC) has been developed to simulate the main types of polar stratospheric clouds (PSC). The parameterisation of the supercooled ternary solutions (STS, type 1b PSC) in the submodel is based on Carslaw et al. (1995b), the thermodynamical approach to simulate ice particles (type 2 PSC) on Marti and Mauersberger (1993). For the formation of nitric acid trihydrate (NAT) particles (type 1a PSC) two different parameterisations exist. The first one is based on an instantaneous thermodynamical approach from Hanson and Mauersberger (1988), the second one (new implemented by Kirner, 2008) considers the growth of the NAT particles with aid of a surface growth factor based on Carslaw et al. (2002). Via namelist switches the NAT parameterisation, as well as some parameters for the NAT and ice formation can be chosen. This publication explains the background of the submodel PSC and the use of the submodel with the goal to simulate realistic PSC in EMAC.