  Interstellar ices are layers of molecules deposited on !ne dust grains in
dark and dense molecular cloud cores. Subsurface ice has been considered in a
few astrochemical models, which have shown that it can be of great importance.
The aim of this work is to introduce an established subsurface ice description
into the state-of-the-art astrochemical model ALCHEMIC. The model has been
developed by the Heidelberg astrochemistry group. The result is an up-to-date
model for interstellar molecular cloud research with possible application for
protoplanetary disks.
