public void TestNewTetrahedralChirality()
{
IChemObjectBuilder builder = RootObject.Builder;
IAtomContainer molecule = builder.NewAtomContainer();
molecule.Atoms.Add(builder.NewAtom("Cl"));
molecule.Atoms.Add(builder.NewAtom("C"));
molecule.Atoms.Add(builder.NewAtom("Br"));
molecule.Atoms.Add(builder.NewAtom("I"));
molecule.Atoms.Add(builder.NewAtom("H"));
molecule.AddBond(molecule.Atoms[0], molecule.Atoms[1], BondOrder.Single);
molecule.AddBond(molecule.Atoms[1], molecule.Atoms[2], BondOrder.Single);
molecule.AddBond(molecule.Atoms[1], molecule.Atoms[3], BondOrder.Single);
molecule.AddBond(molecule.Atoms[1], molecule.Atoms[4], BondOrder.Single);
IAtom[] ligands = new IAtom[] { molecule.Atoms[4], molecule.Atoms[3], molecule.Atoms[2],
molecule.Atoms[0] };
ITetrahedralChirality chirality = builder.NewTetrahedralChirality(molecule.Atoms[1],
ligands, TetrahedralStereo.Clockwise);
Assert.IsNotNull(chirality);
Assert.AreEqual(builder, chirality.Builder);
}
/// <summary>
/// Gets structure from InChI, and converts InChI library data structure into an IAtomContainer.
/// </summary>
/// <param name="builder"></param>
private void GenerateAtomContainerFromInChI(IChemObjectBuilder builder)
{
try
{
output = NInchiWrapper.GetStructureFromInchi(input);
}
catch (NInchiException jie)
{
throw new CDKException("Failed to convert InChI to molecule: " + jie.Message, jie);
}
//molecule = new AtomContainer();
AtomContainer = builder.NewAtomContainer();
var inchiCdkAtomMap = new Dictionary <NInchiAtom, IAtom>();
for (int i = 0; i < output.Atoms.Count; i++)
{
var iAt = output.Atoms[i];
var cAt = builder.NewAtom();
inchiCdkAtomMap[iAt] = cAt;
cAt.Id = "a" + i;
cAt.Symbol = iAt.ElementType;
cAt.AtomicNumber = PeriodicTable.GetAtomicNumber(cAt.Symbol);
// Ignore coordinates - all zero - unless aux info was given... but
// the CDK doesn't have an API to provide that
// InChI does not have unset properties so we set charge,
// hydrogen count (implicit) and isotopic mass
cAt.FormalCharge = iAt.Charge;
cAt.ImplicitHydrogenCount = iAt.ImplicitH;
var isotopicMass = iAt.IsotopicMass;
if (isotopicMass != 0)
{
if (ISOTOPIC_SHIFT_FLAG == (isotopicMass & ISOTOPIC_SHIFT_FLAG))
{
try
{
var massNumber = CDK.IsotopeFactory.GetMajorIsotope(cAt.AtomicNumber).MassNumber.Value;
cAt.MassNumber = massNumber + (isotopicMass - ISOTOPIC_SHIFT_FLAG);
}
catch (IOException e)
{
throw new CDKException("Could not load Isotopes data", e);
}
}
else
{
cAt.MassNumber = isotopicMass;
}
}
AtomContainer.Atoms.Add(cAt);
cAt = AtomContainer.Atoms[AtomContainer.Atoms.Count - 1];
for (int j = 0; j < iAt.ImplicitDeuterium; j++)
{
var deut = builder.NewAtom();
deut.AtomicNumber = 1;
deut.Symbol = "H";
deut.MassNumber = 2;
deut.ImplicitHydrogenCount = 0;
AtomContainer.Atoms.Add(deut);
deut = AtomContainer.Atoms[AtomContainer.Atoms.Count - 1];
var bond = builder.NewBond(cAt, deut, BondOrder.Single);
AtomContainer.Bonds.Add(bond);
}
for (int j = 0; j < iAt.ImplicitTritium; j++)
{
var trit = builder.NewAtom();
trit.AtomicNumber = 1;
trit.Symbol = "H";
trit.MassNumber = 3;
trit.ImplicitHydrogenCount = 0;
AtomContainer.Atoms.Add(trit);
trit = AtomContainer.Atoms[AtomContainer.Atoms.Count - 1];
var bond = builder.NewBond(cAt, trit, BondOrder.Single);
AtomContainer.Bonds.Add(bond);
}
}
for (int i = 0; i < output.Bonds.Count; i++)
{
var iBo = output.Bonds[i];
var atO = inchiCdkAtomMap[iBo.OriginAtom];
var atT = inchiCdkAtomMap[iBo.TargetAtom];
var cBo = builder.NewBond(atO, atT);
var type = iBo.BondType;
switch (type)
{
case INCHI_BOND_TYPE.Single:
cBo.Order = BondOrder.Single;
break;
case INCHI_BOND_TYPE.Double:
cBo.Order = BondOrder.Double;
break;
case INCHI_BOND_TYPE.Triple:
cBo.Order = BondOrder.Triple;
break;
case INCHI_BOND_TYPE.Altern:
cBo.IsAromatic = true;
break;
default:
throw new CDKException("Unknown bond type: " + type);
}
var stereo = iBo.BondStereo;
switch (stereo)
{
// No stereo definition
case INCHI_BOND_STEREO.None:
cBo.Stereo = BondStereo.None;
break;
// Bond ending (fat end of wedge) below the plane
case INCHI_BOND_STEREO.Single1Down:
cBo.Stereo = BondStereo.Down;
break;
// Bond ending (fat end of wedge) above the plane
case INCHI_BOND_STEREO.Single1Up:
cBo.Stereo = BondStereo.Up;
break;
// Bond starting (pointy end of wedge) below the plane
case INCHI_BOND_STEREO.Single2Down:
cBo.Stereo = BondStereo.DownInverted;
break;
// Bond starting (pointy end of wedge) above the plane
case INCHI_BOND_STEREO.Single2Up:
cBo.Stereo = BondStereo.UpInverted;
break;
// Bond with undefined stereochemistry
case INCHI_BOND_STEREO.Single1Either:
case INCHI_BOND_STEREO.DoubleEither:
cBo.Stereo = BondStereo.None;
break;
}
AtomContainer.Bonds.Add(cBo);
}
for (int i = 0; i < output.Stereos.Count; i++)
{
var stereo0d = output.Stereos[i];
if (stereo0d.StereoType == INCHI_STEREOTYPE.Tetrahedral ||
stereo0d.StereoType == INCHI_STEREOTYPE.Allene)
{
var central = stereo0d.CentralAtom;
var neighbours = stereo0d.Neighbors;
var focus = inchiCdkAtomMap[central];
var neighbors = new IAtom[]
{
inchiCdkAtomMap[neighbours[0]],
inchiCdkAtomMap[neighbours[1]],
inchiCdkAtomMap[neighbours[2]],
inchiCdkAtomMap[neighbours[3]]
};
TetrahedralStereo stereo;
// as per JNI InChI doc even is clockwise and odd is
// anti-clockwise
switch (stereo0d.Parity)
{
case INCHI_PARITY.Odd:
stereo = TetrahedralStereo.AntiClockwise;
break;
case INCHI_PARITY.Even:
stereo = TetrahedralStereo.Clockwise;
break;
default:
// CDK Only supports parities of + or -
continue;
}
IStereoElement <IChemObject, IChemObject> stereoElement = null;
switch (stereo0d.StereoType)
{
case INCHI_STEREOTYPE.Tetrahedral:
stereoElement = builder.NewTetrahedralChirality(focus, neighbors, stereo);
break;
case INCHI_STEREOTYPE.Allene:
{
// The periphals (p<i>) and terminals (t<i>) are refering to
// the following atoms. The focus (f) is also shown.
//
// p0 p2
// \ /
// t0 = f = t1
// / \
// p1 p3
var peripherals = neighbors;
var terminals = ExtendedTetrahedral.FindTerminalAtoms(AtomContainer, focus);
// InChI always provides the terminal atoms t0 and t1 as
// periphals, here we find where they are and then add in
// the other explicit atom. As the InChI create hydrogens
// for stereo elements, there will always we an explicit
// atom that can be found - it may be optionally suppressed
// later.
// not much documentation on this (at all) but they appear
// to always be the middle two atoms (index 1, 2) we therefore
// test these first - but handle the other indices just in
// case
foreach (var terminal in terminals)
{
if (peripherals[1].Equals(terminal))
{
peripherals[1] = FindOtherSinglyBonded(AtomContainer, terminal, peripherals[0]);
}
else if (peripherals[2].Equals(terminal))
{
peripherals[2] = FindOtherSinglyBonded(AtomContainer, terminal, peripherals[3]);
}
else if (peripherals[0].Equals(terminal))
{
peripherals[0] = FindOtherSinglyBonded(AtomContainer, terminal, peripherals[1]);
}
else if (peripherals[3].Equals(terminal))
{
peripherals[3] = FindOtherSinglyBonded(AtomContainer, terminal, peripherals[2]);
}
}
stereoElement = new ExtendedTetrahedral(focus, peripherals, stereo);
}
break;
}
Trace.Assert(stereoElement != null);
AtomContainer.StereoElements.Add(stereoElement);
}
else if (stereo0d.StereoType == INCHI_STEREOTYPE.DoubleBond)
{
NInchiAtom[] neighbors = stereo0d.Neighbors;
// from JNI InChI doc
// neighbor[4] : {#X,#A,#B,#Y} in this order
// X central_atom : NO_ATOM
// \ X Y type : INCHI_StereoType_DoubleBond
// A == B \ /
// \ A == B
// Y
var x = inchiCdkAtomMap[neighbors[0]];
var a = inchiCdkAtomMap[neighbors[1]];
var b = inchiCdkAtomMap[neighbors[2]];
var y = inchiCdkAtomMap[neighbors[3]];
// XXX: AtomContainer is doing slow lookup
var stereoBond = AtomContainer.GetBond(a, b);
stereoBond.SetAtoms(new[] { a, b }); // ensure a is first atom
var conformation = DoubleBondConformation.Unset;
switch (stereo0d.Parity)
{
case INCHI_PARITY.Odd:
conformation = DoubleBondConformation.Together;
break;
case INCHI_PARITY.Even:
conformation = DoubleBondConformation.Opposite;
break;
}
// unspecified not stored
if (conformation.IsUnset())
{
continue;
}
AtomContainer.StereoElements.Add(new DoubleBondStereochemistry(stereoBond, new IBond[] { AtomContainer.GetBond(x, a),
AtomContainer.GetBond(b, y) }, conformation));
}
else
{
// TODO - other types of atom parity - double bond, etc
}
}
}