Physicochemical models: source-tailored or generic?
  Physicochemical models can be powerful tools to trace the chemical evolution
of a protostellar system and allow to constrain its physical conditions at
formation. The aim of this work is to assess whether source-tailored modelling
is needed to explain the observed molecular abundances around young, low-mass
protostars or if, and to what extent, generic models can improve our
understanding of the chemistry in the earliest stages of star formation. The
physical conditions and the abundances of simple, most abundant molecules based
on three models are compared. After establishing the discrepancies between the
calculated chemical output, the calculations are redone with the same chemical
model for all three sets of physical input parameters. With the differences
arising from the chemical models eliminated, the output is compared based on
the influence of the physical model. Results suggest that the impact of the
chemical model is small compared to the influence of the physical conditions,
with considered timescales having the most drastic effect. Source-tailored
models may be simpler by design; however, likely do not sufficiently constrain
the physical and chemical parameters within the global picture of star-forming
regions. Generic models with more comprehensive physics may not provide the
optimal match to observations of a particular protostellar system, but allow a
source to be studied in perspective of other star-forming regions.
