  We present simulations of star forming filaments incorporating - to our
knowledge - the largest chemical network used to date on-the-fly in a 3D-MHD
simulation. The network contains 37 chemical species and about 300 selected
reaction rates. For this we use the newly developed package KROME (Grassi et
al. 2014). Our results demonstrate the feasibility of using such a complex
chemical network in 3D-MHD simulations on modern supercomputers. We perform
simulations with different strengths of the interstellar radiation field and
the cosmic ray ionisation rate and find chemical and physical results in
accordance with observations and other recent numerical work.
