RDKit::DGeomHelpers Namespace Reference

## Functions

void | initBoundsMat (DistGeom::BoundsMatrix *mmat, double defaultMin=0.0, double defaultMax=1000.0)
| Set default upper and lower distance bounds in a distance matrix. More...
void | initBoundsMat (DistGeom::BoundsMatPtr mmat, double defaultMin=0.0, double defaultMax=1000.0)
void | setTopolBounds (const ROMol &mol, DistGeom::BoundsMatPtr mmat, bool set15bounds=true, bool scaleVDW=false)
| Set upper and lower distance bounds between atoms in a molecule based on topology. More...
int | EmbedMolecule (ROMol &mol, unsigned int maxIterations=0, int seed=-1, bool clearConfs=true, bool useRandomCoords=false, double boxSizeMult=2.0, bool randNegEig=true, unsigned int numZeroFail=1, const std::map< int, RDGeom::Point3D > *coordMap=0, double optimizerForceTol=1e-3, bool ignoreSmoothingFailures=false, double basinThresh=5.0)
| Compute an embedding (in 3D) for the specified molecule using Distance Geometry. More...

void

EmbedMultipleConfs (ROMol &mol, INT_VECT &res, unsigned int numConfs=10, int numThreads=1, unsigned int maxIterations=30, int seed=-1, bool clearConfs=true, bool useRandomCoords=false, double boxSizeMult=2.0, bool randNegEig=true, unsigned int numZeroFail=1, double pruneRmsThresh=-1.0, const std::map< int, RDGeom::Point3D > *coordMap=0, double optimizerForceTol=1e-3, bool ignoreSmoothingFailures=false, double basinThresh=5.0)

INT_VECT

EmbedMultipleConfs (ROMol &mol, unsigned int numConfs=10, unsigned int maxIterations=30, int seed=-1, bool clearConfs=true, bool useRandomCoords=false, double boxSizeMult=2.0, bool randNegEig=true, unsigned int numZeroFail=1, double pruneRmsThresh=-1.0, const std::map< int, RDGeom::Point3D > *coordMap=0, double optimizerForceTol=1e-3, bool ignoreSmoothingFailures=false, double basinThresh=5.0)

## Function Documentation

int RDKit::DGeomHelpers::EmbedMolecule | ( | ROMol & | mol,
|  | unsigned int | maxIterations = `0`,
|  | int | seed = `-1`,
|  | bool | clearConfs = `true`,
|  | bool | useRandomCoords = `false`,
|  | double | boxSizeMult = `2.0`,
|  | bool | randNegEig = `true`,
|  | unsigned int | numZeroFail = `1`,
|  | const std::map< int, RDGeom::Point3D > * | coordMap = `0`,
|  | double | optimizerForceTol = `1e-3`,
|  | bool | ignoreSmoothingFailures = `false`,
|  | double | basinThresh = `5.0`
| ) |  |

Compute an embedding (in 3D) for the specified molecule using Distance Geometry.

The following operations are performed (in order) here:

1. Build a distance bounds matrix based on the topology, including 1-5 distances but not VDW scaling
2. Triangle smooth this bounds matrix
3. If step 2 fails - repeat step 1, this time without 1-5 bounds and with vdW scaling, and repeat step 2
4. Pick a distance matrix at random using the bounds matrix
5. Compute initial coordinates from the distance matrix
6. Repeat steps 3 and 4 until maxIterations is reached or embedding is successful

7. Adjust initial coordinates by minimizing a Distance Violation error function

   NOTE**: if the molecule has multiple fragments, they will be embedded separately, this means that they will likely occupy the same region of space.

Parameters

  mol | Molecule of interest
  maxIterations | Max. number of times the embedding will be tried if coordinates are not obtained successfully. The default value is 10x the number of atoms.
  seed | provides a seed for the random number generator (so that the same coordinates can be obtained for a molecule on multiple runs) If negative, the RNG will not be seeded.
  clearConfs | Clear all existing conformations on the molecule
  useRandomCoords | Start the embedding from random coordinates instead of using eigenvalues of the distance matrix.
  boxSizeMult | Determines the size of the box that is used for random coordinates. If this is a positive number, the side length will equal the largest element of the distance matrix times `boxSizeMult`. If this is a negative number, the side length will equal `-boxSizeMult` (i.e. independent of the elements of the distance matrix).
  randNegEig | Picks coordinates at random when a embedding process produces negative eigenvalues
  numZeroFail | Fail embedding if we find this many or more zero eigenvalues (within a tolerance)

  coordMap

  a map of int to Point3D, between atom IDs and their locations their locations. If this container is provided, the coordinates are used to set distance constraints on the embedding. The resulting conformer(s) should have distances between the specified atoms that reproduce those between the points in `coordMap`. Because the embedding produces a molecule in an arbitrary reference frame, an alignment step is required to actually reproduce the provided coordinates.

  optimizerForceTol | set the tolerance on forces in the distgeom optimizer (this shouldn't normally be altered in client code).
  ignoreSmoothingFailures | try to embed the molecule even if triangle bounds smoothing fails
  basinThresh | set the basin threshold for the DGeom force field, (this shouldn't normally be altered in client code).

Returns
  ID of the conformations added to the molecule, -1 if the emdedding failed

void RDKit::DGeomHelpers::EmbedMultipleConfs | ( | ROMol & | mol,
|  | INT_VECT & | res,
|  | unsigned int | numConfs = `10`,
|  | int | numThreads = `1`,
|  | unsigned int | maxIterations = `30`,
|  | int | seed = `-1`,
|  | bool | clearConfs = `true`,
|  | bool | useRandomCoords = `false`,
|  | double | boxSizeMult = `2.0`,
|  | bool | randNegEig = `true`,
|  | unsigned int | numZeroFail = `1`,
|  | double | pruneRmsThresh = `-1.0`,
|  | const std::map< int, RDGeom::Point3D > * | coordMap = `0`,
|  | double | optimizerForceTol = `1e-3`,
|  | bool | ignoreSmoothingFailures = `false`,
|  | double | basinThresh = `5.0`
| ) |  |

This is kind of equivalent to calling EmbedMolecule multiple times - just that the bounds matrix is computed only once from the topology

NOTE**: if the molecule has multiple fragments, they will be embedded separately, this means that they will likely occupy the same region of space.

Parameters

  mol | Molecule of interest
  res | Used to return the resulting conformer ids
  numConfs | Number of conformations to be generated
  numThreads | Sets the number of threads to use (more than one thread will only be used if the RDKit was build with multithread support)
  maxIterations | Max. number of times the embedding will be tried if coordinates are not obtained successfully. The default value is 10x the number of atoms.
  seed | provides a seed for the random number generator (so that the same coordinates can be obtained for a molecule on multiple runs). If negative, the RNG will not be seeded.
  clearConfs | Clear all existing conformations on the molecule
  useRandomCoords | Start the embedding from random coordinates instead of using eigenvalues of the distance matrix.
  boxSizeMult | Determines the size of the box that is used for random coordinates. If this is a positive number, the side length will equal the largest element of the distance matrix times `boxSizeMult`. If this is a negative number, the side length will equal `-boxSizeMult` (i.e. independent of the elements of the distance matrix).
  randNegEig | Picks coordinates at random when a embedding process produces negative eigenvalues
  numZeroFail | Fail embedding if we find this many or more zero eigenvalues (within a tolerance)

  pruneRmsThresh

  Retain only the conformations out of 'numConfs' after embedding that are at least this far apart from each other. RMSD is computed on the heavy atoms. Prunining is greedy; i.e. the first embedded conformation is retained and from then on only those that are atleast pruneRmsThresh away from already retained conformations are kept. The pruning is done after embedding and bounds violation minimization. No pruning by default.

  coordMap

  a map of int to Point3D, between atom IDs and their locations their locations. If this container is provided, the coordinates are used to set distance constraints on the embedding. The resulting conformer(s) should have distances between the specified atoms that reproduce those between the points in `coordMap`. Because the embedding produces a molecule in an arbitrary reference frame, an alignment step is required to actually reproduce the provided coordinates.

  optimizerForceTol | set the tolerance on forces in the DGeom optimizer (this shouldn't normally be altered in client code).
  ignoreSmoothingFailures | try to embed the molecule even if triangle bounds smoothing fails
  basinThresh | set the basin threshold for the DGeom force field, (this shouldn't normally be altered in client code).

INT_VECT RDKit::DGeomHelpers::EmbedMultipleConfs | ( | ROMol & | mol,
|  | unsigned int | numConfs = `10`,
|  | unsigned int | maxIterations = `30`,
|  | int | seed = `-1`,
|  | bool | clearConfs = `true`,
|  | bool | useRandomCoords = `false`,
|  | double | boxSizeMult = `2.0`,
|  | bool | randNegEig = `true`,
|  | unsigned int | numZeroFail = `1`,
|  | double | pruneRmsThresh = `-1.0`,
|  | const std::map< int, RDGeom::Point3D > * | coordMap = `0`,
|  | double | optimizerForceTol = `1e-3`,
|  | bool | ignoreSmoothingFailures = `false`,
|  | double | basinThresh = `5.0`
| ) |  |

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

void RDKit::DGeomHelpers::initBoundsMat | ( | DistGeom::BoundsMatrix * | mmat,
|  | double | defaultMin = `0.0`,
|  | double | defaultMax = `1000.0`
| ) |  |

Set default upper and lower distance bounds in a distance matrix.

Parameters

  mmat | pointer to the bounds matrix to be altered
  defaultMin | default value for the lower distance bounds
  defaultMax | default value for the upper distance bounds

void RDKit::DGeomHelpers::initBoundsMat | ( | DistGeom::BoundsMatPtr | mmat,
|  | double | defaultMin = `0.0`,
|  | double | defaultMax = `1000.0`
| ) |  |

void RDKit::DGeomHelpers::setTopolBounds | ( | const ROMol & | mol,
|  | DistGeom::BoundsMatPtr | mmat,
|  | bool | set15bounds = `true`,
|  | bool | scaleVDW = `false`
| ) |  |

Set upper and lower distance bounds between atoms in a molecule based on topology.

This consists of setting 1-2, 1-3 and 1-4 distance based on bond lengths, bond angles and torsion angle ranges. Optionally 1-5 bounds can also be set, in particular, for path that contain rigid 1-4 paths.

The final step involves setting lower bound to the sum of the vdW radii for the remaining atom pairs.

Parameters

  mol | The molecule of interest
  mmat | Bounds matrix to the bounds are written
  set15bounds | If true try to set 1-5 bounds also based on topology
  scaleVDW | If true scale the sum of the vdW radii while setting lower bounds so that a smaller value (0.7*(vdw1 + vdw2) ) is used for paths that are less five bonds apart.

Note For some strained systems the bounds matrix resulting from setting 1-5 bounds may fail triangle smoothing. In these cases it is recommended to back out and recompute the bounds matrix with no 1-5 bounds and with vdW scaling.