diff --git a/autotst/reaction.py b/autotst/reaction.py
index 0c8ba99..ad9cd8c 100644
--- a/autotst/reaction.py
+++ b/autotst/reaction.py
@@ -916,7 +916,7 @@ def rd_embed(self):
         """
         num_conf_attempts = 10000
         if (self.bm is None) or (self.atom_match is None):
-            rdkit.Chem.AllChem.EmbedMultipleConfs(self._rdkit_molecule, num_conf_attempts, randomSeed=1)
+            rdkit.Chem.AllChem.EmbedMultipleConfs(self._rdkit_molecule, num_conf_attempts, randomSeed=400)
 
             self._rdkit_molecule, minEid = self.optimize_rdkit_molecule()
         else:
@@ -927,7 +927,7 @@ def rd_embed(self):
             self._rdkit_molecule.RemoveAllConformers()
             for i in range(0, num_conf_attempts):
                 try:
-                    rdkit.Chem.Pharm3D.EmbedLib.EmbedMol(self._rdkit_molecule, self.bm, atomMatch=self.atom_match)
+                    rdkit.Chem.Pharm3D.EmbedLib.EmbedMol(self._rdkit_molecule, self.bm, atomMatch=self.atom_match, randomSeed=400)
                     break
                 except ValueError:
                     logging.info(
diff --git a/autotst/reaction_test.py b/autotst/reaction_test.py
index 5170129..80698dc 100644
--- a/autotst/reaction_test.py
+++ b/autotst/reaction_test.py
@@ -30,6 +30,7 @@
 
 import os, sys
 import unittest
+import numpy as np
 import ase
 import rdkit.Chem.rdchem
 import rmgpy.reaction
@@ -211,6 +212,16 @@ def test_reaction_families(self):
         _, family = reaction.get_labeled_reaction()
         self.assertEqual(family.lower(), "intra_H_migration".lower())
 
+    def test_initial_ts_geometry_is_deterministic(self):
+        list_of_coords = []
+        my_reaction_smiles = 'CCCC+[OH]_O+[CH2]CCC'
+        for i in range(3):
+            my_reaction = Reaction(label=my_reaction_smiles)
+            list_of_coords.append(my_reaction.ts['forward'][0].ase_molecule)
+
+        for i in range(1, 3):
+            self.assertTrue(np.all(list_of_coords[i].positions == list_of_coords[0].positions))
+
 class TestTS(unittest.TestCase):
 
     def setUp(self):
@@ -242,7 +253,7 @@ def test_rdkit_molecule(self):
         self.assertIsInstance(rdkit_molecule, rdkit.Chem.rdchem.Mol)
         self.assertEquals(len(rdkit_molecule.GetAtoms()), 11)
         self.assertEquals(len(rdkit_molecule.GetBonds()), 9)
-    
+
     def test_pseudo_geometry(self):
         self.assertIsInstance(self.ts._pseudo_geometry, rdkit.Chem.rdchem.RWMol)
         self.assertEquals(len(self.ts._pseudo_geometry.GetBonds()), 10)
diff --git a/autotst/species.py b/autotst/species.py
index 7c0c440..b920c8e 100644
--- a/autotst/species.py
+++ b/autotst/species.py
@@ -278,7 +278,7 @@ def get_rdkit_mol(self):
         assert self.rmg_molecule, "Cannot create an RDKit geometry without an RMG molecule object"
 
         RDMol = self.rmg_molecule.to_rdkit_mol(remove_h=False)
-        rdkit.Chem.AllChem.EmbedMolecule(RDMol)
+        rdkit.Chem.AllChem.EmbedMolecule(RDMol, randomSeed=400)
         self._rdkit_molecule = RDMol
 
         mol_list = rdkit.Chem.AllChem.MolToMolBlock(self.rdkit_molecule).split('\n')
@@ -1093,7 +1093,7 @@ def set_chirality(self, chiral_center_index, stero="R"):
         rdmol.GetAtomWithIdx(chiral_center.atom_index).SetChiralTag(
             centers_dict[stero.upper()])
 
-        rdkit.Chem.rdDistGeom.EmbedMolecule(rdmol)
+        rdkit.Chem.rdDistGeom.EmbedMolecule(rdmol, randomSeed=400)
 
         old_torsions = self.torsions[:] + self.cistrans[:]
 
diff --git a/autotst/species_test.py b/autotst/species_test.py
index 73e4e9b..a2cd4da 100644
--- a/autotst/species_test.py
+++ b/autotst/species_test.py
@@ -45,6 +45,7 @@ class TestConformer(unittest.TestCase):
     def setUp(self):
         self.conformer = Conformer(smiles='CC')
         self.conformer_torsion_test = Conformer(smiles='CC#CC')
+        self.chiral_conformer = Conformer(smiles='ClC=C(C(Cl)N)O')
     def test_rmg_molecules(self):
         self.assertIsInstance(self.conformer.rmg_molecule,rmgpy.molecule.Molecule)
     def test_rdkit_mol(self):
@@ -105,6 +106,18 @@ def test_get_xyz_block(self):
         positions = self.conformer.ase_molecule.arrays["positions"]
         for n in range(len(positions)):
             self.assertTrue((np.array([float(x) for x in xyz_block.split('\n')[n].split()[1:]]) == positions[n]).all())
+    def test_chiral_determinism(self):
+        list_of_coords = []
+        my_chiral_smiles = 'ClC=C(C(Cl)N)O'
+        for i in range(3):
+            my_chiral_conf = autotst.species.Conformer(smiles=my_chiral_smiles)
+            chiral_centers = my_chiral_conf.get_chiral_centers()
+            my_chiral_conf.set_chirality(chiral_centers[0].index, 'R')
+            list_of_coords.append(my_chiral_conf.get_ase_mol())
+        for i in range(1, 3):
+            self.assertTrue(np.all(list_of_coords[i].positions == list_of_coords[0].positions))
+
+
 
 class TestSpecies(unittest.TestCase):
     def setUp(self):
@@ -112,6 +125,13 @@ def setUp(self):
     def test_generate_structures(self):
         self.assertIsInstance(self.species.generate_structures(),dict)
         self.assertIsInstance(list(self.species.generate_structures().values())[0][0],Conformer)
+    def test_initial_mol_is_deterministic(self):
+        list_of_coords = []
+        for i in range(3):
+            new_sp = Species(smiles=["CCC"])
+            list_of_coords.append(new_sp.conformers['CCC'][0].get_ase_mol())
+        for i in range(1, 3):
+            self.assertTrue(np.all(list_of_coords[i].positions == list_of_coords[0].positions))
 
 if __name__ == "__main__":
     unittest.main(testRunner=unittest.TextTestRunner(verbosity=2))