diff --git a/mmtbx/domains_from_pae.py b/mmtbx/domains_from_pae.py
index b2adc28758..d24a512c12 100644
--- a/mmtbx/domains_from_pae.py
+++ b/mmtbx/domains_from_pae.py
@@ -56,7 +56,7 @@ def parse_pae_file(pae_json_file):
 
 def domains_from_pae_matrix_networkx(pae_matrix, pae_power=1,
        pae_cutoff=5, graph_resolution=1, weight_by_ca_ca_distance=False,
-       distance_power=1, distance_model_file=None):
+       distance_power=1, distance_model=None):
     '''
     Takes a predicted aligned error (PAE) matrix representing the predicted error in distances between each
     pair of residues in a model, and uses a graph-based community clustering algorithm to partition the model
@@ -70,11 +70,11 @@ def domains_from_pae_matrix_networkx(pae_matrix, pae_power=1,
         * pae_cutoff (optional, default=5): graph edges will only be created for residue pairs with pae<pae_cutoff
         * graph_resolution (optional, default=1): regulates how aggressively the clustering algorithm is. Smaller values
           lead to larger clusters. Value should be larger than zero, and values larger than 5 are unlikely to be useful.
-        * weight_by_ca_ca_distance (optional, default=False): adjust the edge weighting for each residue pair according 
-          to the distance between CA residues. If this is True, then `distance_model_file` must be provided.
+        * weight_by_ca_ca_distance (optional, default=False): adjust the edge weighting for each residue pair according
+          to the distance between CA residues. If this is True, then `distance_model` must be provided.
         * distance_power (optional, default=1): If `weight_by_ca_ca_distance` is True, then edge weights will be multiplied
           by 1/distance**distance_power.
-        * distance_model_file (optional, default=None): A PDB or mmCIF file containing the model corresponding to the PAE
+        * distance_model (optional, default=None): Model corresponding to the PAE
           matrix. Only needed if `weight_by_ca_ca_distances is True.
     Returns: a series of lists, where each list contains the indices of residues belonging to one cluster.
     '''
@@ -87,9 +87,9 @@ def domains_from_pae_matrix_networkx(pae_matrix, pae_power=1,
     weights = 1/pae_matrix**pae_power
 
     if weight_by_ca_ca_distance:
-      if distance_model_file is None:
-        raise Sorry('If weight_by_ca_ca_distance is True, distance_model_file must be provided!')
-      weights *= weights_from_distance_matrix(distance_model_file, distance_power)
+      if distance_model is None:
+        raise Sorry('If weight_by_ca_ca_distance is True, distance_model must be provided!')
+      weights *= weights_from_distance_matrix(distance_model, distance_power)
 
     g = nx.Graph()
     size = weights.shape[0]
@@ -110,7 +110,7 @@ def domains_from_pae_matrix_networkx(pae_matrix, pae_power=1,
 
 def domains_from_pae_matrix_igraph(pae_matrix, pae_power=1, pae_cutoff=5,
       graph_resolution=1, weight_by_ca_ca_distance=False,
-       distance_power=1, distance_model_file=None):
+       distance_power=1, distance_model=None):
     '''
     Takes a predicted aligned error (PAE) matrix representing the predicted error in distances between each
     pair of residues in a model, and uses a graph-based community clustering algorithm to partition the model
@@ -124,11 +124,11 @@ def domains_from_pae_matrix_igraph(pae_matrix, pae_power=1, pae_cutoff=5,
         * pae_cutoff (optional, default=5): graph edges will only be created for residue pairs with pae<pae_cutoff
         * graph_resolution (optional, default=1): regulates how aggressively the clustering algorithm is. Smaller values
           lead to larger clusters. Value should be larger than zero, and values larger than 5 are unlikely to be useful.
-        * weight_by_ca_ca_distance (optional, default=False): adjust the edge weighting for each residue pair according 
-          to the distance between CA residues. If this is True, then `distance_model_file` must be provided.
+        * weight_by_ca_ca_distance (optional, default=False): adjust the edge weighting for each residue pair according
+          to the distance between CA residues. If this is True, then `distance_model` must be provided.
         * distance_power (optional, default=1): If `weight_by_ca_ca_distance` is True, then edge weights will be multiplied
           by 1/distance**distance_power.
-        * distance_model_file (optional, default=None): A PDB or mmCIF file containing the model corresponding to the PAE
+        * distance_model (optional, default=None):  Model corresponding to the PAE
           matrix. Only needed if `weight_by_ca_ca_distances is True.
 
     Returns: a series of lists, where each list contains the indices of residues belonging to one cluster.
@@ -142,9 +142,9 @@ def domains_from_pae_matrix_igraph(pae_matrix, pae_power=1, pae_cutoff=5,
     weights = 1/pae_matrix**pae_power
 
     if weight_by_ca_ca_distance:
-      if distance_model_file is None:
-        raise Sorry('If weight_by_ca_ca_distance is True, distance_model_file must be provided!')
-      weights *= weights_from_distance_matrix(distance_model_file, distance_power)
+      if distance_model is None:
+        raise Sorry('If weight_by_ca_ca_distance is True, distance_model must be provided!')
+      weights *= weights_from_distance_matrix(distance_model, distance_power)
 
     g = igraph.Graph()
     size = weights.shape[0]
@@ -188,16 +188,9 @@ def flex_matrix_as_numpy_matrix(distances):
   matrix.ravel()[:] = list(distances.as_1d())
   return matrix
 
-def weights_from_distance_matrix(filename, distance_power):
-  from iotbx.data_manager import DataManager
-  dm = DataManager()
-  dm.set_overwrite(True)
-  dm.process_model_file(filename)
-  model = dm.get_model(filename)
-  model.add_crystal_symmetry_if_necessary()
-
+def weights_from_distance_matrix(distance_model , distance_power):
   flex_matrix = distance_matrix(
-    model.apply_selection_string("name CA").get_sites_cart()
+    distance_model.apply_selection_string("name CA").get_sites_cart()
   )
   numpy_matrix = flex_matrix_as_numpy_matrix(flex_matrix)
   return 1/numpy_matrix**distance_power
@@ -224,10 +217,25 @@ def cluster_as_selection(c, first_resno = None):
         selection_string,r_start, r_end)
   return selection_string
 
+def read_model(filename):
+  from iotbx.data_manager import DataManager
+  dm = DataManager()
+  dm.set_overwrite(True)
+  dm.process_model_file(filename)
+  model = dm.get_model(filename)
+  model.add_crystal_symmetry_if_necessary()
+  return model
+
+
 def get_domain_selections_from_pae_matrix(pae_matrix = None,
-      pae_file = None, library = None,
-      pae_power = None, pae_cutoff = None, graph_resolution = None,
-      weight_by_ca_ca_distance = None, distance_power = None, distance_model_file = None,
+      pae_file = None,
+      library = None,
+      pae_power = None,
+      pae_cutoff = None,
+      graph_resolution = None,
+      weight_by_ca_ca_distance = None,
+      distance_power = None,
+      distance_model = None,
       first_resno = None):
 
     if library is None:
@@ -249,7 +257,7 @@ def get_domain_selections_from_pae_matrix(pae_matrix = None,
       "graph_resolution":         graph_resolution,
       "weight_by_ca_ca_distance": weight_by_ca_ca_distance,
       "distance_power":           distance_power,
-      "distance_model_file":      distance_model_file
+      "distance_model":           distance_model
     }
     # Use default values when argument is None
     kwargs = {key: value for key,value in kwargs.items() if value is not None}
diff --git a/mmtbx/process_predicted_model.py b/mmtbx/process_predicted_model.py
index ece85f1c67..e089e6aff1 100644
--- a/mmtbx/process_predicted_model.py
+++ b/mmtbx/process_predicted_model.py
@@ -59,7 +59,7 @@
       .help = Minimum length of a domain to keep (reject at end if smaller).
       .short_caption = Minimum domain length (residues)
 
-    minimum_sequential_residues = 5 
+    minimum_sequential_residues = 5
       .type = int
       .help = Minimum length of a short segment to keep (reject at end ).
       .short_caption = Minimum sequential_residues
@@ -137,6 +137,20 @@
             should be larger than zero, and values larger than 5 are \
             unlikely to be useful
        .short_caption = PAE graph resolution (if PAE matrix supplied)
+
+     weight_by_ca_ca_distance = False
+       .type = bool
+       .help = Adjust the edge weighting for each residue pair according  \
+             to the distance between CA residues. If this is True, \
+             then distance_model_file must be provided. See also distance_power
+       .short_caption = Weight by CA-CA distance (if distance_model supplied)
+
+     distance_power = 1
+       .type = float
+       .help = If weight_by_ca_ca_distance is True, then edge weights will \
+          be multiplied by 1/distance**distance_power.
+       .short_caption = Distance power (for weighting by CA-CA distance)
+
     }
 
     """
@@ -395,9 +409,9 @@ def get_selection_for_short_segments(ph, minimum_sequential_residues):
           chain_id, r.start, r.end))
   selection_string = " or ".join(selections)
   return selection_string
-      
 
-  
+
+
 
 def split_model_by_chainid(m, chainid_list):
   """
@@ -596,6 +610,9 @@ def split_model_with_pae(
      pae_cutoff = 5.,
      pae_graph_resolution = 1.,
      minimum_domain_length = 10,
+     weight_by_ca_ca_distance = False,
+     distance_power = 1,
+     distance_model = None,
      log = sys.stdout):
 
   """
@@ -620,6 +637,14 @@ def split_model_with_pae(
        the clustering algorithm is. Smaller values lead to larger clusters.
        Value should be larger than zero, and values larger than 5 are
         unlikely to be useful
+   weight_by_ca_ca_distance: (optional, default=False): adjust the edge
+        weighting for each residue pair according to the distance between
+        CA residues. If this is True, then distance_model_file must be provided.
+   distance_power (optional, default=1): If weight_by_ca_ca_distance` is True,
+         then edge weights will be multiplied by 1/distance**distance_power.
+   distance_model ((optional, default=None): A PDB or mmCIF file containing
+         the model corresponding to the PAE matrix. Only needed if
+         weight_by_ca_ca_distances is True.
    minimum_domain_length:  if a region is smaller than this, skip completely
 
    Output:
@@ -655,6 +680,9 @@ def split_model_with_pae(
      pae_cutoff = pae_cutoff,
      graph_resolution = pae_graph_resolution,
      first_resno = first_resno,
+     weight_by_ca_ca_distance = weight_by_ca_ca_distance,
+     distance_power = distance_power,
+     distance_model = distance_model,
     )
 
   # And apply to full model
@@ -672,7 +700,7 @@ def split_model_with_pae(
       good_selections.append(selection_string)
     else:
       keep_list.append(False)
-      print("Skipping region '%s' with size of only %s residues" %(
+      print("Skipping region with selection '%s' that contains %s residues" %(
          selection_string,sel.count(True)),
         file = log)
 
diff --git a/mmtbx/regression/tst_domains_from_pae.py b/mmtbx/regression/tst_domains_from_pae.py
index 72ca5d0ce4..037ffd3ea5 100644
--- a/mmtbx/regression/tst_domains_from_pae.py
+++ b/mmtbx/regression/tst_domains_from_pae.py
@@ -14,6 +14,11 @@
 pae_file=os.path.join(data_dir,'pae.json')
 model_file=os.path.join(data_dir, 'pdbs','pae_model.pdb')
 
+from iotbx.data_manager import DataManager
+dm = DataManager()
+distance_model = dm.get_model(model_file)
+distance_model.add_crystal_symmetry_if_necessary()
+
 def tst_01(log = sys.stdout):
 
     args = group_args(
@@ -50,16 +55,18 @@ def tst_02(log = sys.stdout):
       resolution = 1.0,
       weight_by_ca_ca_distance = 1.0,
       distance_power = 1.0,
-      distance_model_file = model_file,
+      distance_model = distance_model,
       select_range = False)
 
+
+
     selections = get_domain_selections_from_pae_matrix(pae_file = args.pae_file,
         library=args.library,
         pae_power = args.pae_power, pae_cutoff = args.pae_cutoff,
          graph_resolution =  args.resolution,
          weight_by_ca_ca_distance = args.weight_by_ca_ca_distance,
          distance_power = args.distance_power,
-         distance_model_file = args.distance_model_file)
+         distance_model = args.distance_model)
     print("Selections:")
     for s in selections:
        print(s)
diff --git a/mmtbx/regression/tst_process_predicted_model.py b/mmtbx/regression/tst_process_predicted_model.py
index d97d5a21d2..88ac5c5b85 100644
--- a/mmtbx/regression/tst_process_predicted_model.py
+++ b/mmtbx/regression/tst_process_predicted_model.py
@@ -27,7 +27,7 @@
 
 
 model_file=os.path.join(data_dir,'fibronectin_af_ca_1358_1537.pdb')
-pae_model_file=os.path.join(data_dir,'pae.pdb')
+pae_model_file=os.path.join(data_dir,'pae_model.pdb')
 pae_file=os.path.join(pae_data_dir,'pae.json')
 
 def tst_01(log = sys.stdout):