GGCHEMPY: A pure Python-based gas-grain chemical code for efficient
  simulation of interstellar chemistry
  In this paper, we present a new gas-grain chemical code for interstellar
clouds written in pure Python (GGCHEMPY). By combining with the
high-performance Python compiler Numba, GGCHEMPY is as efficient as the
Fortran-based version. With the Python features, flexible computational
workflows and extensions become possible. As a showcase, GGCHEMPY is applied to
study the general effects of three-dimensional projection on molecular
distributions using a two-core system which can be easily extended for more
complex cases. By comparing the molecular distribution differences between two
overlapping cores and two merging cores, we summarized the typical chemical
differences such as, N2H+, HC3N, C2S, H2CO, HCN and C2H, which can be used to
interpret 3-D structures in molecular clouds.
