LamellarOrderParameter Class Reference

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Detailed Description

Collective variable for studying phase transitions in block copolymer systems.

This class implements a collective variable based on the Fourier modes of concentration fluctuations.

The value of the collective variable is given by , where is the number of modes supplied, is the wave vector associated with mode , its phase shift, and $a(type_j)$ is the mode coefficient for a particle of type .

The force is calculated as minus the derivative of with respect to particle positions , multiplied by the bias factor.

Inheritance diagram for LamellarOrderParameter:

List of all members.

Public Member Functions
	LamellarOrderParameter (boost::shared_ptr< SystemDefinition > sysdef, const std::vector< Scalar > &mode, const std::vector< int3 > &lattice_vectors, const std::vector< Scalar > &phases, const std::string &suffix="")
virtual void	computeForces (unsigned int timestep)
std::vector< std::string >	getProvidedLogQuantities ()
Scalar	getLogValue (const std::string &quantity, unsigned int timestep)
Scalar	getCurrentValue (unsigned int timestep)
Public Member Functions inherited from CollectiveVariable
	CollectiveVariable (boost::shared_ptr< SystemDefinition > sysdef, const std::string &name)
virtual void	setBiasFactor (Scalar bias)
std::string	getName ()

Protected Member Functions
void	calculateWaveVectors ()
	Helper function to update the wave vectors.

Protected Attributes
std::string	m_log_name
	The log name for this collective variable.
std::vector< int3 >	m_lattice_vectors
	Stores the list of miller indices.
std::vector< Scalar >	m_mode
	Stores the per-type mode coefficients.
Scalar	m_sum
	The current value of the collective variable.
GPUArray< Scalar3 >	m_wave_vectors
	GPUArray of wave vectors.
GPUArray< Scalar2 >	m_fourier_modes
	Fourier modes.
GPUArray< Scalar >	m_phases
	Phase shifts.
Protected Attributes inherited from CollectiveVariable
Scalar	m_bias
std::string	m_cv_name

Private Member Functions
void	calculateFourierModes ()
	Helper function to calculate the Fourier modes.

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Constructor & Destructor Documentation

LamellarOrderParameter	(	boost::shared_ptr< SystemDefinition >	sysdef,
		const std::vector< Scalar > &	mode,
		const std::vector< int3 > &	lattice_vectors,
		const std::vector< Scalar > &	phases,
		const std::string &	suffix = ""
	)

Constructs the collective variable

Parameters:

sysdef	The system definition
mode	The per-type coefficients of the Fourier mode
lattice_vectors	The Miller indices of the mode vector
phases	The phases for every mode
suffix	The suffix appended to the log name for this quantity

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Member Function Documentation

void calculateFourierModes ( )

private

Helper function to calculate the Fourier modes.

Returns a list of fourier modes (for all wave vectors)

void calculateWaveVectors ( )

protected

Helper function to update the wave vectors.

Calculate wave vectors.

void computeForces ( unsigned int  timestep )

virtual

Compute the forces for this collective variable. The force that is written to the force arrays must be multiplied by the bias factor.

Parameters:

timestep

The current value of the time step

Implements CollectiveVariable.

Scalar getCurrentValue ( unsigned int  timestep )

inlinevirtual

Returns the current value of the collective variable

Parameters:

timestep

The current value of the time step

Implements CollectiveVariable.

Scalar getLogValue	(	const std::string &	quantity,
		unsigned int	timestep
	)

Returns the value of a specific log quantity.

Parameters:

quantity	The name of the quantity to return the value of
timestep	The current value of the time step

std::vector<std::string> getProvidedLogQuantities ( )

inline

Returns the names of provided log quantities.

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

• LamellarOrderParameter.h
• LamellarOrderParameter.cc