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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_d(slab):
 """ Determine the distance of space between each layer of atoms along c """

    sorted_sites = sorted(slab, key=lambda site: site.frac_coords[2])
    for i, site in enumerate(sorted_sites):
        if "%.6f" % (site.frac_coords[2]) == \
                        "%.6f" % (sorted_sites[i + 1].frac_coords[2]):
            continue
        else:
            d = abs(site.frac_coords[2] - \
                    sorted_sites[i + 1].frac_coords[2])
            break
    return slab.lattice.get_cartesian_coords([0, 0, d])[2]