# OEMMFFVdw¶

Attention

This API is currently available in C++ and Python.

class OEMMFFVdw : public OEMolPotential::OEMolFunc2


The OEMMFFVdw class defines VdW interaction function using the functional forms used in MMFF94 force field. The function can be initialized with parameters defined in MMFF94 (OEMMFFParams) or MMFF94s (OEMMFF94sParams) force field, or a different set of user defined parameters (OEFFParams) during construction.

The following methods are publicly inherited from OEFunc0:
The following methods are publicly inherited from OEFunc1:
The following methods are publicly inherited from OEFunc2:
The following methods are publicly inherited from OEMolFunc:
The OEMMFFVdw class defines the following public methods:

## Constructors¶

OEMMFFVdw(const OEMMFFVdw &)
OEMMFFVdw(const OEMolPotential::OEFFParams &, bool attract=true)


Default and copy constructors.

Constructs an OEMMFFVdw instance using the specified set of parameters.

The second argument controls whether the attractive part of the VdW potential is included in the gradient calculation. By default, the normal MMFF94 VdW functional form is used. If, however, a boolean value of false is passed as the second constructor argument then the attractive part of each Van der Waals interaction is excluded from calculation.

## operator=¶

OEMMFFVdw &operator=(const OEMMFFVdw &)


The assignment operator.

## Set¶

bool Set(const OESystem::OEBinaryPredicate<OEChem::OEAtomBase, OEChem::OEAtomBase>&)


This method can be used for interaction-level control of the Van der Waals term. Interactions between two atoms are only included if the test of the binary predicate with both atoms returns true. The Set method must be called before the Setup for it to be effective.