Thermostat for isotropic NPT dynamics. More...

#include <thermostat.hpp>

Inheritance diagram for IsotropicNptThermostat:

Collaboration diagram for IsotropicNptThermostat:

Public Member Functions
void	recalc_prefactors (double kT, double piston, std::vector< double > const &mass_list, double time_step)
	Recalculate prefactors.

Public Member Functions inherited from BaseThermostat
void	rng_initialize (uint32_t const seed)
	Initialize or re-initialize the RNG counter with a seed.

void	rng_increment ()
	Increment the RNG counter.

uint64_t	rng_counter () const
	Get current value of the RNG.

void	set_rng_counter (uint64_t value)

bool	is_seed_required () const
	Is the RNG seed required.

uint32_t	rng_seed () const

Static Public Member Functions
static double	sigma (double kT, double gamma, double time_step)
	Calculate the noise prefactor.

static double	sigma_OU (double kT, double gamma, double time_step)
	Calculate the noise prefactor for the exact solution of Orstein-Uhlenbeck equation.

Public Attributes
Parameters
double	gamma0 = 0.
	Friction coefficient of the particles \( \gamma^0 \).

double	gammav = 0.
	Friction coefficient for the box \( \gamma^V \).

Prefactors
std::unordered_map< double, double >	pref_rescale_0
	Particle velocity rescaling at the time step for Orstein-Uhlenbeck equation.

std::unordered_map< double, double >	pref_noise_0
	Particle velocity rescaling noise standard deviation for Orstein-Uhlenbeck equation.

double	pref_rescale_V = 0.
	Volume rescaling at half the time step.

double	pref_noise_V = 0.
	Volume rescaling noise standard deviation for Orstein-Uhlenbeck equation Stores \( \sqrt{k_B T ( 1 - \exp( -2 \frac{\gamma^{0}}{W} dt}) \).

Detailed Description

Thermostat for isotropic NPT dynamics.

Definition at line 277 of file core/thermostat.hpp.

Member Function Documentation

◆ recalc_prefactors()

void IsotropicNptThermostat::recalc_prefactors	(	double	kT,
		double	piston,
		std::vector< double > const &	mass_list,
		double	time_step
	)

inline

Recalculate prefactors.

Needs to be called every time the parameters are changed.

Definition at line 285 of file core/thermostat.hpp.

References gamma0, gammav, pref_noise_0, pref_noise_V, pref_rescale_0, pref_rescale_V, sigma_OU(), and stream.

◆ sigma()

static double IsotropicNptThermostat::sigma	(	double	kT,
		double	gamma,
		double	time_step
	)

inlinestatic

Calculate the noise prefactor.

Evaluates the quantity \( \sqrt{2 k_B T \gamma dt / 2} / \sigma_\eta \) with \( \sigma_\eta \) the standard deviation of the random uniform process \( \eta(t) \).

Definition at line 303 of file core/thermostat.hpp.

References stream.

◆ sigma_OU()

static double IsotropicNptThermostat::sigma_OU	(	double	kT,
		double	gamma,
		double	time_step
	)

inlinestatic

Calculate the noise prefactor for the exact solution of Orstein-Uhlenbeck equation.

Evaluates the quantity \( \sqrt{k_B T (1 - \exp(-2 \gamma dt)} \)

Definition at line 313 of file core/thermostat.hpp.

Referenced by recalc_prefactors().

Member Data Documentation

◆ gamma0

double IsotropicNptThermostat::gamma0 = 0.

Friction coefficient of the particles \( \gamma^0 \).

Definition at line 319 of file core/thermostat.hpp.

Referenced by ScriptInterface::Thermostat::IsotropicNpt::IsotropicNpt(), propagate_therm0_nptiso(), and recalc_prefactors().

◆ gammav

double IsotropicNptThermostat::gammav = 0.

Friction coefficient for the box \( \gamma^V \).

Definition at line 321 of file core/thermostat.hpp.

Referenced by ScriptInterface::Thermostat::IsotropicNpt::IsotropicNpt(), propagate_thermV_nptiso(), and recalc_prefactors().

◆ pref_noise_0

std::unordered_map<double, double> IsotropicNptThermostat::pref_noise_0

Particle velocity rescaling noise standard deviation for Orstein-Uhlenbeck equation.

Stores \( \sqrt{k_B T ( 1 - \exp( -2 \frac{\gamma^{0}}{m} dt}) \)

Definition at line 334 of file core/thermostat.hpp.

Referenced by propagate_therm0_nptiso(), and recalc_prefactors().

◆ pref_noise_V

double IsotropicNptThermostat::pref_noise_V = 0.

Volume rescaling noise standard deviation for Orstein-Uhlenbeck equation Stores \( \sqrt{k_B T ( 1 - \exp( -2 \frac{\gamma^{0}}{W} dt}) \).

Definition at line 343 of file core/thermostat.hpp.

Referenced by propagate_thermV_nptiso(), and recalc_prefactors().

◆ pref_rescale_0

std::unordered_map<double, double> IsotropicNptThermostat::pref_rescale_0

Particle velocity rescaling at the time step for Orstein-Uhlenbeck equation.

Stores \( \exp(-\frac{\gamma^{0}}{m} \cdot dt) \).

Definition at line 329 of file core/thermostat.hpp.

Referenced by propagate_therm0_nptiso(), and recalc_prefactors().

◆ pref_rescale_V

double IsotropicNptThermostat::pref_rescale_V = 0.

Volume rescaling at half the time step.

Stores \( \exp(-\frac{\gamma^{V}}{W} \cdot dt) \).

Definition at line 338 of file core/thermostat.hpp.