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Open Source Chemistry Library
/*
* Copyright (c) 1997 - 2016
* Actelion Pharmaceuticals Ltd.
* Gewerbestrasse 16
* CH-4123 Allschwil, Switzerland
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of the the copyright holder nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
package com.actelion.research.chem;
import com.actelion.research.util.Angle;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
/**
* While the Molecule class covers all primary molecule information as atom and bond properties,
* the atom connectivity and coordinates, its derived class ExtendedMolecule handles secondary,
* i.e. calculated molecule information. Most important are the directly connected atoms and bonds
* of every atom, information about rings and whether they are aromatic, and some atom properties
* that depend on their near neighbors. This calculated information is cached in helper arrays and
* stays valid as long as the molecule's primary information is not changed. High level methods,
* e.g. getPath(), that require valid helper arrays take care of updating the cache themselves.
* Low level methods, e.g. isAromaticAtom(), which typically are called very often, do not check
* the validity of or update the helper arrays themselves for performance reasons. If you use low
* level methods, then you need to make sure that the required helper array information is valid by
* calling ensureHelperArrays().
* Typically you will never instantiate an ExtendedMolecule, but rather use a StereoMolecule.
*/
public class ExtendedMolecule extends Molecule implements Serializable {
static final long serialVersionUID = 0x2006CAFE;
/**
* To interpret a stereo center as fisher projection, all non stereo
* bonds must be vertical and all stereo bonds must be horizontal.
* FISCHER_PROJECTION_LIMIT is the allowed tolerance (currently 5.0 degrees).
*/
public static final float FISCHER_PROJECTION_LIMIT = (float)Math.PI / 36;
public static final float STEREO_ANGLE_LIMIT = (float)Math.PI / 36; // 5 degrees
public static final int cMaxConnAtoms = 16; // ExtendedMolecule is not restricted anymore
// However, this is a suggestion for editors and other classes
transient private int mAtoms,mBonds;
transient private RingCollection mRingSet;
transient private int mPi[];
transient private int mConnAtoms[];
transient private int mAllConnAtoms[];
transient private int mConnAtom[][];
transient private int mConnBond[][];
transient private int mConnBondOrder[][];
public ExtendedMolecule() {
}
public ExtendedMolecule(int maxAtoms, int maxBonds) {
super(maxAtoms, maxBonds);
}
public ExtendedMolecule(Molecule mol) {
super(mol.getMaxAtoms(), mol.getMaxBonds());
mol.copyMolecule(this);
}
/**
* Copies a part of this Molecule into destMol, being defined by a mask of atoms to be included.
* If not all atoms are copied, then destMol is set to be a substructure fragment.
* @param destMol receives the part of this Molecule
* @param includeAtom defines atoms to be copied; its size may be this.getAtoms() or this.getAllAtoms()
* @param recognizeDelocalizedBonds defines whether disconnected delocalized bonds will keep their
* single/double bond status or whether the query feature 'delocalized bond' will be set
* @param atomMap null or int[] not smaller than includeAtom.length; receives atom indices of dest molecule
*/
public void copyMoleculeByAtoms(ExtendedMolecule destMol, boolean[] includeAtom, boolean recognizeDelocalizedBonds, int[] atomMap) {
if (recognizeDelocalizedBonds)
ensureHelperArrays(cHelperRings);
destMol.mAtomList = null;
if (mIsFragment)
destMol.setFragment(true);
int atomCount = includeAtom.length;
if (atomMap == null)
atomMap = new int[atomCount];
destMol.mAllAtoms = 0;
for (int atom=0; atom
* standard P valence is 3, used valence is 4, implicit abnormal valence is 5.
* The molecule is interpreted as O=PH2-OMe. Requires cHelperNeighbours!
* @param atom
* @param neglectExplicitHydrogen
* @return abnormal valence or -1 if valence doesn't exceed standard valence
*/
public int getImplicitHigherValence(int atom, boolean neglectExplicitHydrogen) {
int occupiedValence = getOccupiedValence(atom) - getElectronValenceCorrection(atom);
if (neglectExplicitHydrogen)
occupiedValence -= mAllConnAtoms[atom] - mConnAtoms[atom];
byte[] valenceList = (mAtomicNo[atom] < cAtomValence.length) ?
cAtomValence[mAtomicNo[atom]] : null;
int valence = (valenceList == null) ? cDefaultAtomValence : valenceList[0];
if (occupiedValence <= valence)
return -1;
/* The error may not be the additional hydrogens but an omitted charge.
* Therefore, don't correct and just explain what we have.
* This old handling caused problems with implicit hydrogens in 3D id-coordinates
* because the number og implicit hydrogens was not correctly reproduced during idcode parsing.
* TLS 20-Jun-2015
*
// If we don't neglect hydrogen and don't have allowed higher valences
// then consider explicit hydrogens as errors.
if (!neglectExplicitHydrogen
&& (valenceList == null || valenceList.length == 1)) {
occupiedValence -= mAllConnAtoms[atom] - mConnAtoms[atom];
return (occupiedValence <= valence) ? -1 : occupiedValence;
}
if (valenceList != null)
for (int i=1; (valence 0) {
pathAtom[index-1] = parentAtom[pathAtom[index]];
index--;
}
return graphLevel[parent];
}
if (graphLevel[candidate] == 0) {
graphAtom[++highest] = candidate;
graphLevel[candidate] = graphLevel[parent]+1;
parentAtom[candidate] = parent;
}
}
}
current++;
}
return -1;
}
/**
* Finds bonds of a path that is defined by an atom sequence.
* @param pathAtom pathAtom[0]...[pathLength] -> list of atoms on path
* @param pathBond int array not smaller than pathLength
* @param pathLength no of path bonds == no of path atoms - 1
*/
public void getPathBonds(int[] pathAtom, int[] pathBond, int pathLength) {
ensureHelperArrays(cHelperNeighbours);
for (int i=0; i> 1;
}
occupiedValence -= getElectronValenceCorrection(atom);
int maxValence = getAtomAbnormalValence(atom);
if (maxValence == -1) {
if (mAtomicNo[atom] >= 171 && mAtomicNo[atom] <= 190) {
maxValence = 2;
}
else {
byte[] valenceList = (mAtomicNo[atom] < cAtomValence.length) ?
cAtomValence[mAtomicNo[atom]] : null;
if (valenceList == null) {
maxValence = cDefaultAtomValence;
}
else {
maxValence = valenceList[0];
for (int i=1; (maxValence= 171 && mAtomicNo[atom] <= 190
&& mAllConnAtoms[atom] > 2) // to accomodate for bisulfide bridges
molweight -= (mAllConnAtoms[atom] - 2) * cRoundedMass[1];
}
return molweight;
}
/**
* Simple method to calculate rotatable bonds. This method counts all single
* bonds provided that they
* - are not a terminal bond
* - are not part of a ring
* - are not an amide bond
* - are not the second of two equivalent bonds next to the same triple bond
* @return
*/
public int getRotatableBondCount() {
int rCount = 0;
ensureHelperArrays(Molecule.cHelperRings);
for (int bond=0; bond 1
&& !isAromaticAtom(connAtom)
&& isElectronegative(connAtom)) {
isRotatable = false;
break; // amid bond
}
}
}
}
if (isRotatable && !isPseudoRotatableBond(bond))
rCount++;
}
}
return rCount;
}
/**
* In a consecutive sequence of sp-hybridized atoms multiple single bonds
* cause redundant torsions. Only that single bond with the smallest bond index
* is considered really rotatable; all other single bonds are pseudo rotatable.
* If one/both end(s) of the sp-atom sequence doesn't carry atoms
* outside of the straight line then no bond is considered rotatable.
* A simple terminal single bond
* @param bond
* @return true, if this bond is not considered rotatable because of a redundancy
*/
public boolean isPseudoRotatableBond(int bond) {
if (getBondOrder(bond) != 1)
return false;
for (int i=0; i<2; i++) {
int atom = mBondAtom[i][bond];
int rearAtom = mBondAtom[1-i][bond];
while (mPi[atom] == 2
&& mConnAtoms[atom] == 2
&& mAtomicNo[atom] < 10) {
for (int j=0; j<2; j++) {
int connAtom = mConnAtom[atom][j];
if (connAtom != rearAtom) {
if (mConnAtoms[connAtom] == 1)
return true;
int connBond = mConnBond[atom][j];
if (getBondOrder(connBond) == 1
&& connBond < bond)
return true;
rearAtom = atom;
atom = connAtom;
break;
}
}
}
if (mConnAtoms[atom] == 1)
return true;
}
return false;
}
public int getAromaticRingCount() {
ensureHelperArrays(cHelperRings);
int count = 0;
for (int i=0; i
* This method tells the molecule that current atom/bond parities are valid, even if the
* stereo perception not has been performed. In addition to the stereo parities on may
* declare CIP parities and/or symmetry ranks also to be valid (helperStereoBits != 0).
* This method should be called if no coordinates are available but the parities are valid
* nevertheless, e.g. when the IDCodeParser parses an idcode without coordinates.
* (Note: After idcode parsing unknown stereo centers have parities cAtomParityNone
* instead of cAtomParityUnknown. Thus, calling isStereoCenter(atom) returns false!!!)
* Declaring parities valid prevents the Canonizer to run the stereo recognition again when
* ensureHelperArrays(cHelperParities or higher) is called.
* May also be called after filling valences with explicit hydrogen atoms, which have no
* coordinates, to tell the molecule that the earlier created stereo flags are still valid.
* @param helperStereoBits 0 or combinations of cHelperBitCIP,cHelperBitSymmetry...,cHelperBitIncludeNitrogenParities
*/
public void setParitiesValid(int helperStereoBits) {
mValidHelperArrays |= (cHelperBitsStereo & (cHelperBitParities | helperStereoBits));
}
/**
* This converts one single bond per parity into a stereo up/down bond to
* correctly reflect the given parity. This works for tetrahedral and
* allene atom parities as well as for BINAP type of bond parities.
* Should only be called with valid TH and EZ parities and valid coordinates,
* e.g. after idcode parsing with coordinates or after coordinate generation.
*/
public void setStereoBondsFromParity() {
ensureHelperArrays(cHelperRings); // in case we miss ring and neighbour information
for (int atom=0; atom 4) {
setAtomParity(atom, cAtomParityNone, false);
return;
}
int[] sortedConnMap = getSortedConnMap(atom);
float angle[] = new float[mAllConnAtoms[atom]];
for (int i=0; i sortedConn[i-1]) && lowestConnAtom > mConnAtom[atom][j]) {
lowestConnAtom = mConnAtom[atom][j];
lowestConnIndex = j;
}
}
sortedConn[i] = lowestConnAtom;
if (mConnBond[atom][lowestConnIndex] == preferredBond)
preferredBondIndex = i;
} */
for (int i=1; i angle[2]) && (angle[1] - angle[2] > Math.PI)));
break;
case 1:
inverted = (angle[2] - angle[0] > Math.PI);
break;
case 2:
inverted = (angle[1] - angle[0] < Math.PI);
break;
}
bondType = ((getAtomParity(atom) == cAtomParity1) ^ inverted) ?
cBondTypeUp : cBondTypeDown;
/* // original handling where parity depended solely on the clockwise/anti-clockwise of three angles
bondType = ((getAtomParity(atom) == cAtomParity1)
^ (angle[1] > angle[2])) ?
cBondTypeDown : cBondTypeUp; */
}
else {
int order = 0;
if (angle[1] <= angle[2] && angle[2] <= angle[3]) order = 0;
else if (angle[1] <= angle[3] && angle[3] <= angle[2]) order = 1;
else if (angle[2] <= angle[1] && angle[1] <= angle[3]) order = 2;
else if (angle[2] <= angle[3] && angle[3] <= angle[1]) order = 3;
else if (angle[3] <= angle[1] && angle[1] <= angle[2]) order = 4;
else if (angle[3] <= angle[2] && angle[2] <= angle[1]) order = 5;
bondType = ((getAtomParity(atom) == cAtomParity1)
^ (up_down[order][preferredBondIndex] == 1)) ?
cBondTypeDown : cBondTypeUp;
}
mBondType[preferredBond] = bondType;
}
private boolean setFisherProjectionStereoBondsFromParity(int atom, int[] sortedConnMap, float[] angle) {
int[] direction = new int[mAllConnAtoms[atom]];
int parity = getFisherProjectionParity(atom, sortedConnMap, angle, direction);
if (parity == cAtomParityUnknown)
return false;
int bondType = (getAtomParity(atom) == parity) ? cBondTypeUp : cBondTypeDown;
for (int i=0; i 4)
return false;
boolean[] isUsed = new boolean[4];
for (int i=0; i FISCHER_PROJECTION_LIMIT)
return false;
direction[i] = 3 & (int)(a / (Math.PI/2));
if (isUsed[direction[i]])
return false;
isUsed[direction[i]] = true;
if ((direction[i] & 1) == 0) { // vertical bond
if (mBondType[mConnBond[atom][sortedConnMap[i]]] != cBondTypeSingle)
return false;
}
else {
if (!isStereoBond(mConnBond[atom][sortedConnMap[i]], atom))
return false;
}
}
return isUsed[0] && isUsed[2];
}
private void setAlleneStereoBondFromParity(int atom) {
// find preferred bond to serve as stereobond
if (mConnAtoms[atom] != 2
|| mConnBondOrder[atom][0] != 2
|| mConnBondOrder[atom][1] != 2
|| mConnAtoms[mConnAtom[atom][0]] < 2
|| mConnAtoms[mConnAtom[atom][1]] < 2
|| mPi[mConnAtom[atom][0]] != 1
|| mPi[mConnAtom[atom][1]] != 1) {
setAtomParity(atom, cAtomParityNone, false);
return;
}
int preferredBond = -1;
int preferredAtom = -1;
int preferredAlleneAtom = -1;
int oppositeAlleneAtom = -1;
int bestScore = 0;
for (int i=0; i<2; i++) {
int alleneAtom = mConnAtom[atom][i];
for (int j=0; j connAtom))
highPriorityAtom = connAtom;
}
int[] oppositeAtom = new int[2];
int oppositeAtoms = 0;
for (int i=0; i oppositeAtom[1]) {
int temp = oppositeAtom[0];
oppositeAtom[0] = oppositeAtom[1];
oppositeAtom[1] = temp;
}
float hpAngleDif = getAngleDif(alleneAngle,
getBondAngle(oppositeAlleneAtom, oppositeAtom[0]));
float lpAngleDif = getAngleDif(alleneAngle,
getBondAngle(oppositeAlleneAtom, oppositeAtom[1]));
angleDif = hpAngleDif - lpAngleDif;
}
else {
angleDif = getAngleDif(alleneAngle,
getBondAngle(oppositeAlleneAtom, oppositeAtom[0]));
}
if ((angleDif < 0.0)
^ (getAtomParity(atom) == cAtomParity1)
^ (highPriorityAtom == preferredAtom))
mBondType[preferredBond] = cBondTypeUp;
else
mBondType[preferredBond] = cBondTypeDown;
}
/**
* In case bond is a BINAP kind of chiral bond with defined parity,
* then the preferred neighbour single bond is converted into a
* stereo bond to correctly reflect its defined parity.
* @param bond
*/
public void setStereoBondFromBondParity(int bond) {
// set an optimal bond to up/down to reflect the atom parity
if (getBondParity(bond) == Molecule.cBondParityNone
|| getBondParity(bond) == Molecule.cBondParityUnknown
|| !isBINAPChiralityBond(bond))
return;
int preferredBond = -1;
int preferredAtom = -1;
int preferredBINAPAtom = -1;
int oppositeBINAPAtom = -1;
int bestScore = 0;
for (int i=0; i<2; i++) {
int atom = mBondAtom[i][bond];
for (int j=0; j connAtom))
highPriorityAtom = connAtom;
}
int[] oppositeAtom = new int[2];
int oppositeAtoms = 0;
for (int i=0; i oppositeAtom[1]) {
int temp = oppositeAtom[0];
oppositeAtom[0] = oppositeAtom[1];
oppositeAtom[1] = temp;
}
float hpAngleDif = getAngleDif(binapAngle, getBondAngle(oppositeBINAPAtom, oppositeAtom[0]));
float lpAngleDif = getAngleDif(binapAngle, getBondAngle(oppositeBINAPAtom, oppositeAtom[1]));
angleDif = hpAngleDif - lpAngleDif;
}
else {
angleDif = getAngleDif(binapAngle, getBondAngle(oppositeBINAPAtom, oppositeAtom[0]));
}
if ((angleDif < 0.0)
^ (getBondParity(bond) == cBondParityZor2)
^ (highPriorityAtom == preferredAtom))
mBondType[preferredBond] = cBondTypeUp;
else
mBondType[preferredBond] = cBondTypeDown;
}
protected boolean bondsAreParallel(float angle1, float angle2) {
float angleDif = Math.abs(getAngleDif(angle1, angle2));
return (angleDif < 0.08 || angleDif > Math.PI - 0.08);
}
private int preferredTHStereoBond(int atom) {
// If we have two (anti-)parallel bonds, the we need to select
// that one of those that is closest to the other bonds.
float[] angle = new float[mAllConnAtoms[atom]];
for (int i=0; i= 6)
for (int i=0; i= 6)
for (int i=0; i= 5) {
int orthoSubstituentCount = 0;
for (int j=0; j= 3)
orthoSubstituentCount++;
}
if (orthoSubstituentCount == 2
|| (orthoSubstituentCount == 1 && mConnAtoms[atom] == 3))
continue; // the nitrogen is rotated out of PI-plane
}
return true;
}
// vinyloge amides, etc.
for (int j=0; j 2)
orthoSubstituentCount++;
}
for (int j=0; j 2)
orthoSubstituentCount++;
}
return (orthoSubstituentCount > 2);
}
protected boolean validateBondType(int bond, int type) {
boolean ok = super.validateBondType(bond, type);
if (ok && type == cBondTypeCross) {
ensureHelperArrays(Molecule.cHelperRings);
ok &= !isSmallRingBond(bond);
}
return ok;
}
public void validate() throws Exception {
float avbl = getAverageBondLength();
float minDistanceSquare = avbl * avbl / 16.0f;
for (int atom1=1; atom1 getMaxValence(atom))
throw new Exception("atom valence exceeded");
allCharge += mAtomCharge[atom];
}
if (allCharge != 0)
throw new Exception("unbalanced atom charge");
}
/**
* Normalizes different forms of functional groups (e.g. nitro)
* to a preferred one. This step should precede any canonicalization.
* @return true if the molecule was changed
*/
public boolean normalizeAmbiguousBonds() {
ensureHelperArrays(cHelperNeighbours);
boolean found = false;
for (int atom=0; atom 0
&& mAtomCharge[mBondAtom[1][bond]] < 0) {
atom1 = mBondAtom[0][bond];
atom2 = mBondAtom[1][bond];
}
else if (mAtomCharge[mBondAtom[0][bond]] < 0
&& mAtomCharge[mBondAtom[1][bond]] > 0) {
atom1 = mBondAtom[1][bond];
atom2 = mBondAtom[0][bond];
}
else
continue;
if (mAtomicNo[atom1] < 9)
if (getOccupiedValence(atom1) > 3)
continue;
mAtomCharge[atom1] -= 1;
mAtomCharge[atom2] += 1;
if (getBondOrder(bond) == 1)
mBondType[bond] = cBondTypeDouble;
else
mBondType[bond] = cBondTypeTriple;
mValidHelperArrays = cHelperNone;
}
}
int overallCharge = 0;
int negativeAtomCount = 0;
int negativeAdjustableCharge = 0;
for (int atom=0; atom 0) {
if (!hasNegativeNeighbour(atom) && isElectronegative(atom)) {
int chargeReduction = Math.min(getImplicitHydrogens(atom), mAtomCharge[atom]);
if (chargeReduction != 0 && negativeAdjustableCharge >= chargeReduction) {
overallChargeChange -= chargeReduction;
negativeAdjustableCharge += chargeReduction;
mAtomCharge[atom] -= chargeReduction;
mValidHelperArrays &= cHelperNeighbours;
}
}
}
}
if (overallChargeChange < 0) {
int[] negativeAtom = new int[negativeAtomCount];
negativeAtomCount = 0;
for (int atom=0; atom=negativeAtom.length-negativeAtomCount); i--) {
int atom = negativeAtom[i] & 0x0000FFFF;
if (isElectronegative(atom)) {
int chargeReduction = Math.min(-overallChargeChange, -mAtomCharge[atom]);
overallChargeChange += chargeReduction;
mAtomCharge[atom] += chargeReduction;
mValidHelperArrays &= cHelperNeighbours;
}
}
}
return overallCharge;
}
/**
* @param atom
* @return true if atom has a neighbour with a negative charge
*/
private boolean hasNegativeNeighbour(int atom) {
for (int i=0; i 0)
return true;
return false;
}
/**
* While the Molecule class covers all primary molecule information, its derived class
* ExtendedMolecule handles secondary, i.e. calculated molecule information, which is cached
* in helper arrays and stays valid as long as the molecule's primary information is not changed.
* Most methods of ExtendedMolecule require some of the helper array's information. High level
* methods, e.g. getPath(), take care of updating an outdated cache themselves. Low level methods,
* e.g. isAromaticAtom(), which typically are called very often, do not check for validity
* nor update the helper arrays themselves. If you use low level methods, then you need to make
* sure that the needed helper array information is valid by this method.
* For performance reasons there are distinct levels of helper information. (A higher
* level always includes all properties of the previous level):
* cHelperNeighbours: explicit hydrogen atoms are moved to the end of the atom table and
* bonds leading to them are moved to the end of the bond table. This way algorithms can skip
* hydrogen atoms easily. For every atom directly connected atoms and bonds (with and without
* hydrogens) are determined. The number of pi electrons is counted.
* cHelperRings: Aromatic and non-aromatic rings are detected. Atom and bond ring
* properties are set and a ring collection provides a total set of small rings (7 or less atoms).
* Atoms being in allylic/benzylic or stabilized (neighbor of a carbonyl or similar group) position
* are flagged as such.
* cHelperParities: Atom (tetrahedral or axial) and bond (E/Z or atrop) parities are calculated
* from the stereo configurations.
* cHelperCIP: Cahn-Ingold-Prelog stereo information for atoms and bonds.
*
cHelperParities and cHelperCIP require a StereoMolecule!!!
* @param required one of cHelperNeighbours,cHelperRings,cHelperParities,cHelperCIP
* @return true if the molecule was changed
*/
public void ensureHelperArrays(int required) {
// cHelperNeighbours: mConnAtoms,mConnBonds,mPi for all atoms
// cHelperRings: rings,aromaticity/allylic/stabilized for non-H-atoms only
// cHelperParities: stereo parities for non-H-atoms/bonds only
// cHelperCIP: mCanonizer, stereo parities for non-H-atoms/bonds only
if ((required & ~mValidHelperArrays) == 0)
return;
if ((mValidHelperArrays & cHelperBitNeighbours) == 0) {
handleHydrogens();
calculateNeighbours();
mValidHelperArrays |= cHelperBitNeighbours;
if (validateQueryFeatures()) {
handleHydrogens();
calculateNeighbours();
}
}
if ((required & ~mValidHelperArrays) == 0)
return;
if ((mValidHelperArrays & cHelperBitRings) == 0) {
for (int atom=0; atom 1) {
if (mAtomicNo[mConnAtom[connAtom][j]] == 6)
mAtomFlags[atom] |= cAtomFlagAllylic;
else {
if (!isAromaticBond(mConnBond[connAtom][j])
&& isElectronegative(mConnAtom[connAtom][j]))
mAtomFlags[atom] |= cAtomFlagStabilized;
}
}
}
}
}
// propagate stabilized flags to vinylic positions
while (true) {
boolean found = false;
for (int atom=0; atom 0
&& ((cAtomFlagStabilized | cAtomFlagAromatic)
& mAtomFlags[atom]) == cAtomFlagStabilized) {
for (int i=0; i 1) {
int connAtom = mConnAtom[atom][i];
int connBond = mConnBond[atom][i];
for (int j=0; j
* This method moves all simple hydrogen atoms and associated bonds to the end of the atom/bond tables.
* It sets mAtoms to exclude simple hydrogen atoms and mBonds to exclude bonds leading to them.
* Simple hydrogens are not deleted, though. They are always displayed and the stereo perception
* still considers up/down bonds leading to hydrogen atoms. Most other functions, however, can
* happily neglect them.
* mConnAtoms/mConnBonds/mConnBondOrder are neither used nor updated.
* Note: This method changes the order among the non-hydrogen atoms. To translate to the original
* order use getHandleHydrogenMap() before calling ensureHelperArrays() if the original atom order is relevant.
*/
private void handleHydrogens() {
// find all hydrogens that are connected to a non-H atom and therefore can be implicit
boolean[] isSimpleHydrogen = new boolean[mAllAtoms];
for (int bond=0; bond= 0) && isSimpleHydrogen[lastNonHAtom]);
for (int atom=0; atom= 0) && isHydrogenBond[lastNonHBond]);
for (int bond=0; bond= 0 && isSimpleHydrogen[lastNonHAtom]) {
map[lastNonHAtom] = lastNonHAtom;
lastNonHAtom--;
}
for (int atom=0; atom<=lastNonHAtom; atom++) {
if (isSimpleHydrogen[atom]) {
map[atom] = lastNonHAtom;
map[lastNonHAtom] = atom;
lastNonHAtom--;
while (lastNonHAtom >= 0 && isSimpleHydrogen[lastNonHAtom]) {
map[lastNonHAtom] = lastNonHAtom;
lastNonHAtom--;
}
}
else {
map[atom] = atom;
}
}
return map;
}
public boolean isSimpleHydrogen(int atom) {
return mAtomicNo[atom] == 1 && mAtomMass[atom] == 0
&& (mAtomCustomLabel == null || mAtomCustomLabel[atom] == null);
}
/**
* Removes all plain explicit hydrogens atoms from the molecule, converting them
* effectively to implicit ones. If an associated bond is a stereo bond indicating
* a specific configuration, then another bond is converted to a stereo bond to reflect
* the correct stereo geometry. If the removal of a hydrogen atom would change an atom's
* implicit valance, the atom's abnormal valence is set accordingly.
*/
public void removeExplicitHydrogens() {
ensureHelperArrays(cHelperParities); // to calculate stereo center parities
mAllAtoms = mAtoms;
mAllBonds = mBonds;
for (int atom=0; atom 1)
mPi[atom] += order + order - 2;
else if (mBondType[bnd] == cBondTypeDelocalized)
mPi[atom] = 2;
}
}
}
for(int atom=0; atom 3)
mAtomFlags[atom] |= cAtomFlags4RingBonds;
}
for (int ringNo=0; ringNo= getMaxValence(atom))
mAtomQueryFeatures[atom] &= ~(cAtomQFNoMoreNeighbours | cAtomQFMoreNeighbours);
// approximate explicit hydrogens by query features
// and remove explicit hydrogens except those with stereo bonds
boolean deleteHydrogens = false;
for (int atom=0; atom 0) {
if ((mAtomQueryFeatures[atom] & cAtomQFNoMoreNeighbours) == 0) {
if (getFreeValence(atom) == 0)
mAtomQueryFeatures[atom] |= cAtomQFNoMoreNeighbours;
else {
// add query feature hydrogen to explicit hydrogens
int queryFeatureHydrogens = 0;
if ((mAtomQueryFeatures[atom] & cAtomQFNot0Hydrogen) == cAtomQFNot0Hydrogen)
queryFeatureHydrogens++;
if ((mAtomQueryFeatures[atom] & cAtomQFHydrogen) == (cAtomQFNot0Hydrogen | cAtomQFNot1Hydrogen))
queryFeatureHydrogens++;
mAtomQueryFeatures[atom] &= ~cAtomQFHydrogen;
if (getFreeValence(atom) <= queryFeatureHydrogens)
mAtomQueryFeatures[atom] |= cAtomQFNoMoreNeighbours;
else if (queryFeatureHydrogens == 0)
mAtomQueryFeatures[atom] |= cAtomQFNot0Hydrogen;
else // queryFeatureHydrogens > 1
mAtomQueryFeatures[atom] |= (cAtomQFNot0Hydrogen | cAtomQFNot1Hydrogen);
}
}
for (int i=mConnAtoms[atom]; i © 2015 - 2025 Weber Informatics LLC | Privacy Policy