A generalization of the Weeks-Chandler-Andersen (WCA) potential. More...

#include <WeeksChandlerAndersen_DistanceOffset.hpp>

Inheritance diagram for OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >:

Collaboration diagram for OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >:

Public Member Functions
OPENMPCD_CUDA_HOST_AND_DEVICE	WeeksChandlerAndersen_DistanceOffset (const T epsilon, const T sigma, const T d)
	The constructor. More...

OPENMPCD_CUDA_HOST_AND_DEVICE Vector3D< T >	force (const Vector3D< T > &R) const
	Returns the force vector of the interaction for a given position vector. More...

OPENMPCD_CUDA_HOST_AND_DEVICE T	potential (const Vector3D< T > &R) const
	Returns the potential of the interaction for a given position vector. More...

OPENMPCD_CUDA_HOST_AND_DEVICE T	getEpsilon () const
	Returns the \( \epsilon \) parameter. More...

OPENMPCD_CUDA_HOST_AND_DEVICE T	getSigma () const
	Returns the \( \sigma \) parameter. More...

OPENMPCD_CUDA_HOST_AND_DEVICE T	getD () const
	Returns the \( D \) parameter. More...

virtual OPENMPCD_CUDA_HOST_AND_DEVICE Vector3D< FP >	force (const Vector3D< FP > &Rvec) const=0
	Returns the force vector of the interaction for a given position vector. More...

virtual OPENMPCD_CUDA_HOST_AND_DEVICE FP	potential (const Vector3D< FP > &Rvec) const=0
	Returns the potential of the interaction for a given position vector. More...

const OPENMPCD_CUDA_HOST_AND_DEVICE Vector3D< FP >	forceOnR1DueToR2 (const Vector3D< FP > &r1, const Vector3D< FP > &r2) const
	Returns the force exerted on the particle at `r1` due to the particle at `r2`. More...

Detailed Description

template<typename T = FP>
class OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >

A generalization of the Weeks-Chandler-Andersen (WCA) potential.

The Weeks-Chandler-Andersen potential has been introduced by Weeks, Chandler, and Andersen, in J. Chem. Phys. 54, 5237 (1971). DOI: 10.1063/1.1674820

This generalization introduces an offset \( D \) of the particle distance \( r \). With \( \epsilon \) and \( sigma \) being parameters, the interaction potential is given by

\[ 4 * \epsilon * \left( \left( \frac{ \sigma }{ r - D } \right)^{12} - \left( \frac{ \sigma }{ r - D } \right)^{6} + \frac{ 1 }{ 4 } \right) * \theta \left( 2^{1/6} \sigma - r + D \right) \]

with \( \theta \left( x \right) \) being the Heaviside step function, which is \( 1 \) if \( x > 0 \), and \( 0 \) otherwise.

Definition at line 39 of file WeeksChandlerAndersen_DistanceOffset.hpp.

Constructor & Destructor Documentation

◆ WeeksChandlerAndersen_DistanceOffset()

template<typename T = FP>

OPENMPCD_CUDA_HOST_AND_DEVICE OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >::WeeksChandlerAndersen_DistanceOffset	(	const T	epsilon,
		const T	sigma,
		const T	d
	)

inline

The constructor.

Exceptions

OpenMPCD::AssertionException If OPENMPCD_DEBUG is defined, throws if either epsilon < 0, sigma < 0, or d < 0.

Parameters

[in]	epsilon	The \( \epsilon \) parameter.
[in]	sigma	The \( \sigma \) parameter.
[in]	d	The \( D \) parameter.

Definition at line 54 of file WeeksChandlerAndersen_DistanceOffset.hpp.

Member Function Documentation

◆ force() [1/2]

virtual OPENMPCD_CUDA_HOST_AND_DEVICE Vector3D<FP > OpenMPCD::PairPotentials::Base< FP >::force ( const Vector3D< T > & Rvec ) const

pure virtualinherited

Returns the force vector of the interaction for a given position vector.

This function returns the directional derivative

\[ - \nabla_R V \left( \vec{R} \right) \]

where \( \vec{R} \) is the Rvec parameter, \( V \) is the potential as given by the potential function, and \( \nabla_R V \) is the gradient of \( V \) with respect to \( \vec{R} \).

Parameters

[in] Rvec The relative position vector.

◆ force() [2/2]

template<typename T = FP>

OPENMPCD_CUDA_HOST_AND_DEVICE Vector3D<T> OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >::force ( const Vector3D< T > & R ) const

inline

Returns the force vector of the interaction for a given position vector.

This function returns the directional derivative

\[ - \nabla_R V \left( \vec{R} \right) \]

where \( \vec{R} \) is the R parameter, \( V \) is the potential as given by the potential function, and \( \nabla_R V \) is the gradient of \( V \) with respect to \( \vec{R} \).

Exceptions

OpenMPCD::AssertionException If OPENMPCD_DEBUG is defined, throws if R.getMagnitudeSquared() - d * d <= 0.

Parameters

[in] R The relative position vector.

Definition at line 79 of file WeeksChandlerAndersen_DistanceOffset.hpp.

◆ forceOnR1DueToR2()

const OPENMPCD_CUDA_HOST_AND_DEVICE Vector3D<FP > OpenMPCD::PairPotentials::Base< FP >::forceOnR1DueToR2	(	const Vector3D< T > &	r1,
		const Vector3D< T > &	r2
	)		const

inlineinherited

Returns the force exerted on the particle at r1 due to the particle at r2.

Parameters

[in]	r1	The position of the first particle.
[in]	r2	The position of the second particle.

Definition at line 65 of file PairPotentials/Base.hpp.

◆ getD()

template<typename T = FP>

OPENMPCD_CUDA_HOST_AND_DEVICE T OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >::getD ( ) const

inline

Returns the \( D \) parameter.

Definition at line 157 of file WeeksChandlerAndersen_DistanceOffset.hpp.

◆ getEpsilon()

template<typename T = FP>

OPENMPCD_CUDA_HOST_AND_DEVICE T OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >::getEpsilon ( ) const

inline

Returns the \( \epsilon \) parameter.

Definition at line 139 of file WeeksChandlerAndersen_DistanceOffset.hpp.

◆ getSigma()

template<typename T = FP>

OPENMPCD_CUDA_HOST_AND_DEVICE T OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >::getSigma ( ) const

inline

Returns the \( \sigma \) parameter.

Definition at line 148 of file WeeksChandlerAndersen_DistanceOffset.hpp.

◆ potential() [1/2]

virtual OPENMPCD_CUDA_HOST_AND_DEVICE FP OpenMPCD::PairPotentials::Base< FP >::potential ( const Vector3D< T > & Rvec ) const

pure virtualinherited

Returns the potential of the interaction for a given position vector.

Parameters

[in] Rvec The relative position vector.

◆ potential() [2/2]

template<typename T = FP>

OPENMPCD_CUDA_HOST_AND_DEVICE T OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >::potential ( const Vector3D< T > & R ) const

inline

Returns the potential of the interaction for a given position vector.

Exceptions

OpenMPCD::AssertionException If OPENMPCD_DEBUG is defined, throws if R.getMagnitudeSquared() - d * d <= 0.

Parameters

[in] R The relative position vector.

Definition at line 112 of file WeeksChandlerAndersen_DistanceOffset.hpp.

The documentation for this class was generated from the following file:

WeeksChandlerAndersen_DistanceOffset.hpp

Public Member Functions

Detailed Description

template<typename T = FP> class OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >

Constructor & Destructor Documentation

◆ WeeksChandlerAndersen_DistanceOffset()

Member Function Documentation

◆ force() [1/2]

◆ force() [2/2]

◆ forceOnR1DueToR2()

◆ getD()

◆ getEpsilon()

◆ getSigma()

◆ potential() [1/2]

◆ potential() [2/2]

template<typename T = FP>
class OpenMPCD::PairPotentials::WeeksChandlerAndersen_DistanceOffset< T >