  Arlequin coupling coefficient is essential for concurrent FE-MD models with
overlapping domains, but the calculation of its value is quite difficult when
the geometry of the coupling region is complicated. In this work, we introduce
a general procedure for the preprocessing of a concurrent FE-MD model, given
that the mesh and atoms have already been created. The procedure is independent
of the geometry of the coupling region and can be used for both 2D and 3D
problems. The procedure includes steps of determining the relative positions of
atoms inside the FE elements in the coupling region, as well as computing the
Arlequin coupling coefficient for an arbitrary point inside the coupling region
or on its boundary. Two approaches are provided for determining the
coefficient: the direct approach and the temperature approach.
