docs: def minimum_geometry(self, symmetry_measure_type=None, max_csm=None):
          """
          Returns the geometry with the minimum continuous symmetry measure of this ChemicalEnvironments
          :return: tuple (symbol, csm) with symbol being the geometry with the minimum continuous symmetry measure and
          csm being the continuous symmetry measure associted to it
          :raise: ValueError if no coordination geometry is found in this ChemicalEnvironments object
          """
          if len(self.coord_geoms) == 0:
              return None
          cglist = [cg for cg in self.coord_geoms]
          if symmetry_measure_type is None:
              csms = np.array([self.coord_geoms[cg]['other_symmetry_measures']['csm_wcs_ctwcc'] for cg in cglist])
          else:
              csms = np.array([self.coord_geoms[cg]['other_symmetry_measures'][symmetry_measure_type] for cg in cglist])
          csmlist = [self.coord_geoms[cg] for cg in cglist]
          imin = np.argmin(csms)
          if max_csm is not None:
              if csmlist[imin] > max_csm:
                  return None
          return cglist[imin], csmlist[imin]