• The model object (ddx_type in Fortran) collects all the parameters which control the calculation, like the chosen continuum solvation model, the dielectric permittivity, the information about the discretization, cavity information (the number, centers, and radii of the spheres) and similar. Furthermore, it contains all the precomputed constants which depend on the geometry of the system, and contains the preallocated workspaces, such that most of the memory allocation is done during the initialization phase. This object does not contain variables which depend on the solute's density, like RHSs or solutions.