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Open Source Chemistry Library
/*
* Copyright 2013-2020 Thomas Sander, openmolecules.org
*
* 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 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 HOLDER 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.
*
* @author Thomas Sander
*/
package org.openmolecules.chem.conf.gen;
import com.actelion.research.chem.Canonizer;
import com.actelion.research.chem.Coordinates;
import com.actelion.research.chem.Molecule;
import com.actelion.research.chem.StereoMolecule;
import com.actelion.research.chem.conf.Conformer;
import com.actelion.research.chem.conf.TorsionDB;
import com.actelion.research.chem.conf.VDWRadii;
import com.actelion.research.util.DoubleFormat;
import com.actelion.research.util.IntArrayComparator;
import org.openmolecules.chem.conf.so.ConformationSelfOrganizer;
import org.openmolecules.chem.conf.so.SelfOrganizedConformer;
import java.util.Arrays;
import java.util.Random;
import java.util.TreeMap;
/**
* This class generates 3D-conformers of a given molecule using the following strategy:
* All rotatable, non-ring bonds are determined.
* Fragments separated by rotatable bonds are considered rigid, but there may be more than one possible
* fragment conformer, e.g. chair- and boat conformers of a saturated 6-membered ring.
* These atom coordinate sets of rigid fragments are handed out by a dedicated RigidFragmentProvider instance,
* which either generates them using a self organization algorithm, or which takes it from a cache.
* For every rotatable bond a list of preferred torsion angles is determined based on from a COD statistics
* of similar bond environments.
* For individual torsion values likelihoods are estimated based on frequency and atom collisions of vicinal fragments.
* A dedicated (systematic, biased or random) torsion set strategy delivers collision-free torsion sets, i.e. conformers.
*
* For generating conformers in multiple threads, every thread needs its own ConformerGenerator instance.
* If they use a RigidFragmentCache, then the cache is shared among all ConformerGenerators.
*/
public class ConformerGenerator {
public static final int STRATEGY_LIKELY_SYSTEMATIC = 1;
public static final int STRATEGY_PURE_RANDOM = 2;
public static final int STRATEGY_LIKELY_RANDOM = 3;
public static final int STRATEGY_ADAPTIVE_RANDOM = 4;
protected static final double VDW_TOLERANCE_HYDROGEN = 0.80; // factor on VDW radii for minimum tolerated non bound atom distances
protected static final double VDW_TOLERANCE_OTHER = 0.80; // factor on VDW radii for minimum tolerated non bound atom distances
private static final int ESCAPE_ANGLE = 8; // degrees to rotate two adjacent rotatable bonds to escape collisions
private static final int ESCAPE_STEPS = 4; // how often we apply this rotation trying to solve the collision
private static final double MIN_ESCAPE_GAIN_PER_STEP = 0.05;
private StereoMolecule mMolecule;
private TreeMap mBaseConformerMap;
private RotatableBond[] mRotatableBond;
private RigidFragment[] mRigidFragment;
private ConformationSelfOrganizer mSelfOrganizer;
private RigidFragmentProvider mRigidFragmentProvider;
private TorsionSetStrategy mTorsionSetStrategy;
private TorsionSet mTorsionSet;
private long mRandomSeed;
private int mDisconnectedFragmentCount,mConformerCount;
private boolean mUseSelfOrganizerIfAllFails;
private double mContribution;
private int[] mFragmentNo,mDisconnectedFragmentNo,mDisconnectedFragmentSize;
private boolean[][] mSkipCollisionCheck;
private Random mRandom;
public static final boolean PRINT_TORSION_AND_FRAGMENT_LIKELYHOODS = false;
public static final boolean PRINT_DEBUG_INDEXES = false;
public static final boolean PRINT_EXIT_REASON = false;
public static final boolean PRINT_ELIMINATION_RULES_WITH_STRUCTURES = false;
public static final String DW_FRAGMENTS_FILE = "/home/thomas/data/debug/conformationGeneratorFragments.dwar";
public String mDiagnosticCollisionString,mDiagnosticTorsionString; // TODO get rid of this
public int[] mDiagnosticCollisionAtoms; // TODO get rid of this
public static boolean WRITE_DW_FRAGMENT_FILE = false;
/**
* Adds explicit hydrogen atoms where they are implicit by filling valences
* and adapting for atom charges. New hydrogen atoms receive new 2D-coordinates
* by equally locating them between those two neighbors with the widest angle between
* their bonds. Any stereo configurations deducible from 2D-coordinates are retained.
* @param mol
*/
public static void addHydrogenAtoms(StereoMolecule mol) {
// We may have parities but empty coordinates. In this case we need to protect parities.
boolean paritiesValid = (mol.getHelperArrayStatus() & Molecule.cHelperBitParities) != 0;
mol.ensureHelperArrays(Molecule.cHelperNeighbours);
int[] implicitHydrogen = new int[mol.getAtoms()];
for (int atom=0; atom(new IntArrayComparator());
return getNextConformer();
}
else {
ConformationSelfOrganizer sampler = new ConformationSelfOrganizer(mol, true);
Conformer conformer = sampler.generateOneConformer(mRandomSeed);
separateDisconnectedFragments(conformer);
return conformer;
}
}
/**
* Don't call this method directly. Rather call initializeConformers() !!!
* Adds implicit hydrogens to the molecule and determines all rotatable bonds,
* which are not part of a ring. Generates rigid fragments between rotatable bonds.
* The base conformer is constructed by connecting all rigid fragments using the
* most frequent torsions. Atoms of different fragments in the base conformer may
* collide. In order to obtain collision free conformers choose a TorsionStrategy
* and call getNextConformer() at least once.
* @param mol
* @param use60degreeSteps use 60 degree steps for every rotatable bond instead of torsion DB
*/
protected boolean initialize(StereoMolecule mol, boolean use60degreeSteps) {
mSelfOrganizer = null;
mol.ensureHelperArrays(Molecule.cHelperNeighbours);
for (int atom=0; atom mol.getMaxValence(atom))
return false;
addHydrogenAtoms(mol);
// we need to protect explicit hydrogens in the fragments that we create from mol
mol.setHydrogenProtection(true);
int[] atomParity = null;
int[] bondParity = null;
boolean[] atomParityIsPseudo = null;
boolean[] bondParityIsPseudo = null;
// if we have parities and no atom coordinates, parities cannot be correctly recreated
// by the Canonizer and, thus, need to be cached and copied back after the symmetry detection.
if ((mol.getHelperArrayStatus() & Molecule.cHelperBitParities) != 0) {
atomParity = new int[mol.getAtoms()];
atomParityIsPseudo = new boolean[mol.getAtoms()];
for (int atom=0; atom");
// writer.newLine();
// writer.write("");
// writer.newLine();
// writer.write("");
// writer.newLine();
// writer.write("");
// writer.newLine();
// writer.write("");
// writer.newLine();
// writer.write("");
// writer.newLine();
// writer.write("");
// writer.newLine();
// writer.write("Structure\tcoords");
// writer.newLine();
// for (Rigid3DFragment f:mRigidFragment) {
// StereoMolecule[] fragment = f.getFragment();
// for (int i=0; i
Integer.compare(b2.getSmallerSideAtomCount(), b1.getSmallerSideAtomCount()) );
// TODO this is actually only used with random conformers. Using a conformer mode
// may save some time, if systematic conformers are created.
initializeCollisionCheck();
return true;
}
/**
* After calling initializeConformers() this method returns the number of rotatable bonds,
* which are used to separate the molecule into rigid fragments.
* @return
*/
public int getRotatableBondCount() {
return mRotatableBond == null ? 0 : mRotatableBond.length;
}
private Conformer getBaseConformer(int[] fragmentPermutation) {
Conformer baseConformer = mBaseConformerMap.get(fragmentPermutation);
if (baseConformer != null)
return baseConformer;
baseConformer = new Conformer(mMolecule);
boolean[] isAttached = new boolean[mRigidFragment.length];
for (RotatableBond rb:mRotatableBond)
rb.connectFragments(baseConformer, isAttached, fragmentPermutation);
// for separated fragments without connection points we need to get coordinates
for (int i=0; i=0; j--)
mRotatableBond[j].rotateToIndex(conformer, mTorsionSet.getTorsionIndexes()[j]);
if (WRITE_DW_FRAGMENT_FILE) {
mDiagnosticTorsionString = ""+mTorsionSet.getTorsionIndexes()[0];
for (int i=1; i" + mTorsionSet.getConformerIndexes()[0];
for (int i=1; i mTorsionSetStrategy.calculateCollisionTolerance()) {
//System.out.println("COLLIDES!");
// TODO remove
String idcode,coords;
int elimRules;
if (PRINT_ELIMINATION_RULES_WITH_STRUCTURES) {
Canonizer can = new Canonizer(conformer.toMolecule(null));
idcode = can.getIDCode();
coords = can.getEncodedCoordinates();
elimRules = mTorsionSetStrategy.getEliminationRuleList().size();
}
mTorsionSet = mTorsionSetStrategy.getNextTorsionSet(mTorsionSet);
// TODO remove
if (PRINT_ELIMINATION_RULES_WITH_STRUCTURES) {
if (elimRules != mTorsionSetStrategy.getEliminationRuleList().size()) {
if (elimRules == 0)
System.out.println("idcode\tidcoords\telimRules\tstrategy");
StringBuilder sb = new StringBuilder();
for (int i = elimRules; i < mTorsionSetStrategy.getEliminationRuleList().size(); i++) {
TorsionSetEliminationRule rule = mTorsionSetStrategy.getEliminationRuleList().get(i);
sb.append(mTorsionSetStrategy.eliminationRuleString(rule));
sb.append(" m:" + Long.toHexString(rule.getMask()[0]));
sb.append(" d:" + Long.toHexString(rule.getData()[0]));
sb.append("");
}
System.out.println(idcode + "\t" + coords + "\t" + sb.toString() + "\tlikelyRandom");
}}
if (mTorsionSet != null || mConformerCount != 0)
continue;
if (mUseSelfOrganizerIfAllFails) {
mSelfOrganizer = new ConformationSelfOrganizer(mMolecule, true);
mSelfOrganizer.initializeConformers(mRandomSeed, -1);
conformer = mSelfOrganizer.getNextConformer();
if (conformer != null) {
separateDisconnectedFragments(conformer);
mConformerCount++;
return conformer;
}
}
// we didn't get any torsion set that didn't collide; take the best we had
mTorsionSet = mTorsionSetStrategy.getBestCollidingTorsionIndexes();
conformer = new Conformer(getBaseConformer(mTorsionSet.getConformerIndexes()));
for (int j=mRotatableBond.length-1; j>=0; j--)
mRotatableBond[j].rotateToIndex(conformer, mTorsionSet.getTorsionIndexes()[j]);
mBaseConformerMap = null; // we are finished with conformers
}
//System.out.println("passed collision check! "+mTorsionSet.toString());
separateDisconnectedFragments(conformer);
mContribution = mTorsionSetStrategy.getContribution(mTorsionSet);
mTorsionSet.setUsed();
mConformerCount++;
if(torsion_set_out != null) {
torsion_set_out[0] = new TorsionSet(mTorsionSet);
}
return conformer;
}
return null;
}
/**
* @return count of valid delivered conformers
*/
public int getConformerCount() {
return mConformerCount;
}
/**
* Calculates the potential count of conformers by multiplying degrees of freedom
* (torsions per rotatable bond & rigid fragment multiplicities).
* Cannot be called before calling initializeConformers().
* @return
*/
public int getPotentialConformerCount() {
return (mTorsionSetStrategy == null) ? 1 : mTorsionSetStrategy.getPermutationCount();
}
/**
* With best current knowledge about colliding torsion combinations
* and based on the individual frequencies of currently active torsions
* this method returns the conformers's overall contribution to the
* total set of non colliding conformers.
* @return this conformer's contribution to all conformers
*/
public double getPreviousConformerContribution() {
return mRotatableBond == null ? 1f : mContribution;
}
/**
* If a molecule has at least one rotatable bond if all permutations
* of torsions collide beyond a tolerated strain, then the standard
* behaviour of this class is to return that clashing conformer with
* the lowest strain.
* If passing true to this method, the ConformerGenerator will use
* the ConformerSelfOrganizer in these cases to generate conformers.
* getNextConformer will then deliver conformers until the self organization
* fails to create new conformers.
* @param b
*/
public void setUseSelfOrganizerIfAllFails(boolean b) {
mUseSelfOrganizerIfAllFails = b;
}
/**
* One of the initializeConformers() methods needs to be called, before getting individual
* conformers of the same molecule by getNextConformer().
* Open valences of the passed molecule are filled with hydrogen atoms.
* The passed molecule may repeatedly be used as container for a new conformer's atom
* coordinates, if it is passed as parameter to getNextConformer().
* This method uses the STRATEGY_LIKELY_RANDOM strategy with a maximum of 100.000 distinct
* torsion sets and uses torsions from crystallographic data.
* @param mol will be saturated with hydrogen atoms
* @return false if there is a structure problem
*/
public boolean initializeConformers(StereoMolecule mol) {
return initializeConformers(mol, STRATEGY_LIKELY_RANDOM, 100000, false);
}
/**
* One of the initializeConformers() methods needs to be called, before getting individual
* conformers of the same molecule by getNextConformer().
* Open valences of the passed molecule are filled with hydrogen atoms.
* The passed molecule may repeatedly be used as container for a new conformer's atom
* coordinates, if it is passed as parameter to getNextConformer().
* @param mol will be saturated with hydrogen atoms
* @param strategy one of the STRATEGY_ constants
* @param maxTorsionSets maximum number of distinct torsion sets the strategy will try (default 100000)
* @param use60degreeSteps use 60 degree steps for every rotatable bond instead of torsion DB
* @return false if there is a structure problem
*/
public boolean initializeConformers(StereoMolecule mol, int strategy, int maxTorsionSets, boolean use60degreeSteps) {
if (!initialize(mol, use60degreeSteps))
return false;
if (mRotatableBond == null) {
mSelfOrganizer = new ConformationSelfOrganizer(mol, true);
mSelfOrganizer.initializeConformers(mRandomSeed, -1);
}
else {
switch(strategy) {
case STRATEGY_PURE_RANDOM:
mTorsionSetStrategy = new TorsionSetStrategyRandom(mRotatableBond, mRigidFragment, false, mRandomSeed);
break;
case STRATEGY_LIKELY_RANDOM:
mTorsionSetStrategy = new TorsionSetStrategyRandom(mRotatableBond, mRigidFragment, true, mRandomSeed);
break;
case STRATEGY_ADAPTIVE_RANDOM:
mTorsionSetStrategy = new TorsionSetStrategyAdaptiveRandom(mRotatableBond, mRigidFragment, true, true, mRandomSeed);
break;
case STRATEGY_LIKELY_SYSTEMATIC:
mTorsionSetStrategy = new TorsionSetStrategyLikelySystematic(mRotatableBond, mRigidFragment);
break;
}
mTorsionSetStrategy.setMaxTotalCount(maxTorsionSets);
mBaseConformerMap = new TreeMap(new IntArrayComparator());
}
return true;
}
/**
* Moves disconnected fragments along Z-axis such that there is an
* empty z-space SEPARATION_DISTANCE thick between the fragments.
* @param conformer
*/
private void separateDisconnectedFragments(Conformer conformer) {
final double SEPARATION_DISTANCE = 3.0;
if (mDisconnectedFragmentCount > 1) {
double[] meanX = new double[mDisconnectedFragmentCount];
double[] meanY = new double[mDisconnectedFragmentCount];
double[] minZ = new double[mDisconnectedFragmentCount];
double[] maxZ = new double[mDisconnectedFragmentCount];
for (int i=0; i conformer.getZ(atom))
minZ[mDisconnectedFragmentNo[atom]] = conformer.getZ(atom);
if (maxZ[mDisconnectedFragmentNo[atom]] < conformer.getZ(atom))
maxZ[mDisconnectedFragmentNo[atom]] = conformer.getZ(atom);
}
for (int i=0; i";
mDiagnosticCollisionString = mDiagnosticCollisionString+"a1:"+atom1+" f1:"+mFragmentNo[atom1]+" a2:"+atom2+" f2:"+mFragmentNo[atom2]+" distance:"+distance+" min:"+minDistance;
if (mDiagnosticCollisionAtoms == null) {
mDiagnosticCollisionAtoms = new int[2];
mDiagnosticCollisionAtoms[0] = atom1;
mDiagnosticCollisionAtoms[1] = atom2;
}
}
if (collisionIntensityMatrix == null)
collisionIntensityMatrix = new double[mRigidFragment.length][];
int f1 = mFragmentNo[atom1];
int f2 = mFragmentNo[atom2];
if (f1 < f2) {
if (collisionIntensityMatrix[f2] == null)
collisionIntensityMatrix[f2] = new double[f2];
collisionIntensityMatrix[f2][f1] += collisionIntensity;
}
else {
if (collisionIntensityMatrix[f1] == null)
collisionIntensityMatrix[f1] = new double[f1];
collisionIntensityMatrix[f1][f2] += collisionIntensity;
}
}
}
}
}
}
}
}
torsionSet.setCollisionIntensity(collisionIntensitySum, collisionIntensityMatrix);
return (collisionIntensitySum != 0);
}
/**
* If we have collisions between two fragments that have two rotatable bonds in between,
* then we try to rotate both rotatable bonds in any of these situations stepwise
* by a small angle to reduce the collision intensity sum. If we achieve a sufficient
* improvement without hampering the rest of the molecule, the passed conformer is modified.
* @param origConformer
* @param torsionSet
* @return true if successful; false if no fix possible that reduces total collision intensity below tolerance
*/
private boolean tryFixCollisions(Conformer origConformer, TorsionSet torsionSet) {
double[][] origCollisionIntensityMatrix = torsionSet.getCollisionIntensityMatrix();
double remainingCollisionIntensity = 0;
for (int f1=1; f1 TorsionSetStrategy.MAX_ALLOWED_COLLISION_INTENSITY)
return false;
boolean changeDone = false;
Conformer conformer = null;
Conformer backup = null;
double origCollisionIntensitySum = torsionSet.getCollisionIntensitySum();
for (int f1=1; f1 MIN_ESCAPE_GAIN_PER_STEP
&& mTorsionSetStrategy.getBondsBetweenFragments(f1, f2).length == 2) {
int[] rotatableBond = mTorsionSetStrategy.getBondsBetweenFragments(f1, f2);
int angle = (mRandom.nextDouble() < 0.5) ? -ESCAPE_ANGLE : ESCAPE_ANGLE;
double origCollisionIntensity = origCollisionIntensityMatrix[f1][f2];
for (int i=1; i<=ESCAPE_STEPS; i++) {
// make sure we keep the original coordinates
if (conformer == null)
conformer = new Conformer(origConformer);
else if (backup == null)
backup = new Conformer(conformer);
else
backup.copyFrom(conformer);
for (int bond : rotatableBond)
mRotatableBond[bond].rotateTo(conformer, (short) (conformer.getBondTorsion(bond) + i*angle));
double localCollisionIntensity = calculateCollisionIntensity(conformer, mRigidFragment[f1], mRigidFragment[f2]);
if (localCollisionIntensity < origCollisionIntensity - MIN_ESCAPE_GAIN_PER_STEP) {
origCollisionIntensity = localCollisionIntensity;
changeDone = true;
// not enough collision intensity left for correction
if (localCollisionIntensity < MIN_ESCAPE_GAIN_PER_STEP)
break;
}
else {
if (backup != null)
conformer.copyFrom(backup);
else
conformer.copyFrom(origConformer);
break;
}
}
}
}
}
}
if (!changeDone)
return false;
checkCollision(conformer, torsionSet);
if (torsionSet.getCollisionIntensitySum() >= origCollisionIntensitySum) {
// local improvement causes worsening somewhere else
torsionSet.setCollisionIntensity(origCollisionIntensitySum, origCollisionIntensityMatrix);
return false;
}
origConformer.copyFrom(conformer);
return true;
}
private double calculateCollisionIntensity(Conformer conformer, RigidFragment f1, RigidFragment f2) {
double collisionIntensitySum = 0;
for (int i=0; i=0; j--) {
Conformer ci = new Conformer(conformer);
mRotatableBond[j].rotateToIndex(ci, torsionIndexes[j]);
if(false) { System.out.print(torsionIndexes[j]+ " "); }
}
//System.out.println("passed collision check! "+mTorsionSet.toString());
separateDisconnectedFragments(conformer);
return conformer;
}
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