define set_rdkit_ring_dihedrals and make test

arc/species/converter.py

@@ -1852,6 +1852,49 @@ def set_rdkit_dihedrals(conf, rd_mol, torsion, deg_increment=None, deg_abs=None)
     return new_xyz
 
 
+def set_rdkit_ring_dihedrals(rd_mol, ring_head, ring_tail, torsions, dihedrals):
+    """
+    A helper function for setting dihedral angles in a ring using RDKit.
+
+    Args:
+        rd_mol: The respective RDKit molecule.
+        ring_head: The first atom index of the ring(0-indexed).
+        ring_tail: The last atom index of the ring(0-indexed).
+        torsions: A list of torsions, each corresponding to a dihedral.
+        dihedrals: A list of dihedral angles in degrees, each corresponding to a torsion.
+
+    Example of a 6-membered ring:
+        ring_head = 0
+        ring_tail = 5
+        torsions = [(0, 1, 2, 3), (1, 2, 3, 4), (2, 3, 4, 5)]
+        dihedrals = [30, 300, 30]
+    
+    Returns:
+        dict: The xyz with the new dihedral, ordered according to the map.
+    """
+
+    rd_mol_mod = Chem.RWMol(rd_mol)
+    rd_mol_mod.RemoveBond(ring_head, ring_tail)
+    Chem.SanitizeMol(rd_mol_mod)
+    conf_mod = rd_mol_mod.GetConformer()
+    for torsion, dihedral in zip(torsions, dihedrals):
+        torsion_0_indexed = [tor - 0 for tor in torsion]
+        set_rdkit_dihedrals(conf_mod, rd_mol_mod, torsion_0_indexed, deg_abs=dihedral)
+
+    rd_mol_mod.AddBond(ring_head, ring_tail, Chem.BondType.SINGLE)
+    Chem.SanitizeMol(rd_mol_mod)
+    Chem.AllChem.MMFFOptimizeMolecule(rd_mol_mod)
+    conf_mod = rd_mol_mod.GetConformer()
+
+    coords = list()
+    symbols = list()
+    for i, atom in enumerate(list(rd_mol_mod.GetAtoms())):
+        coords.append([conf_mod.GetAtomPosition(i).x, conf_mod.GetAtomPosition(i).y, conf_mod.GetAtomPosition(i).z])
+        symbols.append(atom.GetSymbol())
+    new_xyz = xyz_from_data(coords=coords, symbols=symbols)
+    return new_xyz
+
+
 def check_isomorphism(mol1, mol2, filter_structures=True, convert_to_single_bonds=False):
     """
     Convert ``mol1`` and ``mol2`` to RMG Species objects, and generate resonance structures.

arc/species/converter_test.py

@@ -4066,6 +4066,43 @@ def test_set_rdkit_dihedrals(self):
 H       2.16336803    0.09985803    0.03295192"""
         self.assertEqual(converter.xyz_to_str(new_xyz4), expected_xyz4)
 
+    def test_set_rdkit_ring_dihedrals(self):
+        """Test setting the dihedral angles of an RDKit ring molecule"""
+        xyz_original = """C       1.17528959    0.88689342   -0.09425887
+C      -0.23165323    1.40815606   -0.37444021
+C      -1.28915380    0.60789983    0.38119602
+C      -1.17528947   -0.88689346    0.09425817
+C       0.23165279   -1.40815571    0.37444068
+C       1.28915350   -0.60789979   -0.38119592
+H       1.90063595    1.43610053   -0.70501194
+H       1.43190556    1.07695419    0.95523181
+H      -0.29672067    2.46483469   -0.09164586
+H      -0.43309289    1.35229514   -1.45133707
+H      -2.28822258    0.96189799    0.10312701
+H      -1.17664390    0.78164432    1.45848873
+H      -1.43190253   -1.07695588   -0.95523291
+H      -1.90063264   -1.43610606    0.70501042
+H       0.29671416   -2.46483479    0.09164748
+H       0.43309139   -1.35229454    1.45133785
+H       1.17664469   -0.78164459   -1.45848883
+H       2.28822409   -0.96189136   -0.10312655"""
+        xyz_original = converter.str_to_xyz(xyz_original)
+
+        ring_head = 0
+        ring_tail = 5
+        torsions = [(0, 1, 2, 3), (1, 2, 3, 4), (2, 3, 4, 5)]
+        dihedrals = [29.167577928701704, 299.8936870462789, 29.167577208303104]
+
+        s_mol, b_mol = converter.molecules_from_xyz(xyz_original)
+        mol = b_mol if b_mol is not None else s_mol
+        _, rd_mol = converter.rdkit_conf_from_mol(mol, xyz_original)
+
+        xyz_final = converter.set_rdkit_ring_dihedrals(rd_mol, ring_head, ring_tail, torsions, dihedrals)
+
+        self.assertAlmostEqual(calculate_dihedral_angle(xyz_final,[0,1,2,3]), 29.167577928701704, 2)
+        self.assertAlmostEqual(calculate_dihedral_angle(xyz_final,[1,2,3,4]), 299.8936870462789,  2)
+        self.assertAlmostEqual(calculate_dihedral_angle(xyz_final,[2,3,4,5]), 29.167577208303104, 2)
+
     def test_get_center_of_mass(self):
         """Test calculating the center of mass for coordinates"""
         xyz = """O       1.28706525    0.52121353    0.04219198