diff --git a/just_psf/typology_maker.py b/just_psf/typology_maker.py
new file mode 100644
index 0000000..758084e
--- /dev/null
+++ b/just_psf/typology_maker.py
@@ -0,0 +1,151 @@
+from typing import Union
+
+import networkx
+from scipy.spatial import distance_matrix
+
+from just_psf import logger
+from just_psf.geometry import Geometry
+from just_psf.topology import Topology
+
+
+l_logger = logger.getChild(__name__)
+
+
+COVALENT_RADII = {
+    # from 10.1039/B801115J
+    'H': 0.31,
+    'He': 0.28,
+    'Li': 1.28,
+    'Be': 0.96,
+    'B': 0.84,
+    'C': 0.76,
+    'N': 0.71,
+    'O': 0.66,
+    'F': 0.57,
+    'Ne': 0.58,
+    'Na': 1.66,
+    'Mg': 1.41,
+    'Al': 1.21,
+    'Si': 1.11,
+    'P': 1.07,
+    'S': 1.05,
+    'Cl': 1.02,
+    'Ar': 1.06,
+    'K': 2.03,
+    'Ca': 1.76,
+    'Sc': 1.70,
+    'Ti': 1.60,
+    'V': 1.53,
+    'Cr': 1.39,
+    'Mn': 1.39,
+    'Fe': 1.32,
+    'Co': 1.26,
+    'Ni': 1.24,
+    'Cu': 1.32,
+    'Zn': 1.22,
+    'Ga': 1.22,
+    'Ge': 1.20,
+    'As': 1.19,
+    'Se': 1.20,
+    'Br': 1.20,
+    'Kr': 1.16,
+    'Rb': 2.20,
+    'Sr': 1.95,
+    'Y': 1.90,
+    'Zr': 1.75,
+    'Nb': 1.64,
+    'Mo': 1.54,
+    'Tc': 1.47,
+    'Ru': 1.46,
+    'Rh': 1.42,
+    'Pd': 1.39,
+    'Ag': 1.45,
+    'Cd': 1.44,
+    'In': 1.42,
+    'Sn': 1.39,
+    'Sb': 1.39,
+    'Te': 1.38,
+    'I': 1.39,
+    'Xe': 1.40,
+    'Cs': 2.44,
+    'Ba': 2.15,
+    'La': 2.07,
+    'Ce': 2.04,
+    'Pr': 2.03,
+    'Nd': 2.01,
+    'Pm': 1.99,
+    'Sm': 1.98,
+    'Eu': 1.98,
+    'Gd': 1.96,
+    'Tb': 1.94,
+    'Dy': 1.92,
+    'Ho': 1.92,
+    'Er': 1.89,
+    'Tm': 1.90,
+    'Yb': 1.87,
+    'Lu': 1.87,
+    'Hf': 1.75,
+    'Ta': 1.70,
+    'W': 1.62,
+    'Re': 1.51,
+    'Os': 1.44,
+    'Ir': 1.41,
+    'Pt': 1.36,
+    'Au': 1.36,
+    'Hg': 1.32,
+    'Tl': 1.45,
+    'Pb': 1.46,
+    'Bi': 1.48,
+    'Po': 1.40,
+    'At': 1.50,
+    'Rn': 1.50,
+    'Fr': 2.60,
+    'Ra': 2.21,
+    'Ac': 2.15,
+    'Th': 2.06,
+    'Pa': 2.00,
+    'U': 1.96,
+    'Np': 1.90,
+    'Pu': 1.87,
+    'Am': 1.80,
+    'Cm': 1.69,
+}
+
+
+class TopologyMaker:
+    def __init__(self, geometry: Union[str, Geometry], threshold: float = 1.1):
+        if type(geometry) is str:
+            with open(geometry) as f:
+                self.geometry = Geometry.from_xyz(f)
+        elif type(geometry) is Geometry:
+            self.geometry = geometry
+        else:
+            raise TypeError('geometry')
+
+        self.g = networkx.Graph()
+        self.g.add_nodes_from(range(len(geometry)))
+
+        # get bonds
+        l_logger.info('compute distances')
+        self._guess_bonds(threshold)
+
+    def _guess_bonds(self, threshold: float = 1.1):
+        """Guess which atom are linked to which using a distance matrix.
+        May lead to incorrect results for strange bonds (e.g., metalic)
+        """
+        distances = distance_matrix(self.geometry.positions, self.geometry.positions)
+        for i in range(len(self.geometry)):
+            cri = COVALENT_RADII[self.geometry.symbols[i]]
+            for j in range(i + 1, len(self.geometry)):
+                crj = COVALENT_RADII[self.geometry.symbols[j]]
+                if distances[i, j] < threshold * (cri + crj):
+                    self.g.add_edge(i, j)
+
+    def topology(self) -> Topology:
+        """
+        1. Get entities (i.e., subset of the graph with no edges with the rest)
+        2. Run a list of (unique) triplet and quadruplet
+           (with, i.e., i<j<k and i<j<k<l to find all angles and dihedrals)
+        3. Be happy with that and go for Topology ;)
+        """
+        pass
diff --git a/pyproject.toml b/pyproject.toml
index 872d431..c365d2e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,6 +29,8 @@ classifiers = [
 
 dependencies = [
     "numpy",
+    "scipy",
+    "networkx"
 ]
 
 [project.optional-dependencies]
diff --git a/tests/test_topology_maker.py b/tests/test_topology_maker.py
new file mode 100644
index 0000000..9bbc3fc
--- /dev/null
+++ b/tests/test_topology_maker.py
@@ -0,0 +1,9 @@
+from just_psf.typology_maker import TopologyMaker
+
+
+def test_guess_bonds(geometry_fluoroethylene, topology_fluoroethylene):
+    maker = TopologyMaker(geometry_fluoroethylene)
+
+    # check every bond was found
+    for bond in topology_fluoroethylene.bonds:
+        assert bond in maker.g.edges