Charge_Extra Class Reference

charge extrapolation method More...

#include <charge_extra.h>

Collaboration diagram for Charge_Extra:

Public Member Functions
	Charge_Extra ()
	~Charge_Extra ()
void	Init_CE (const int &nspin, const int &natom, const int &nrxx, const std::string chg_extrap)
	Initialization of viriables used in charge extrapolation methods.
void	extrapolate_charge (Parallel_Grid *Pgrid, UnitCell &ucell, Charge *chr, Structure_Factor *sf, std::ofstream &ofs_running, std::ofstream &ofs_warning)
	charge extrapolation method
void	update_all_dis (const UnitCell &ucell)
	update displacements
void	update_delta_rho (const UnitCell &ucell, const Charge *chr, const Structure_Factor *sf)
	update the difference of charge density

Private Member Functions
void	find_alpha_and_beta (const int &natom, std::ofstream &ofs_running, std::ofstream &ofs_warning)
	determine alpha and beta

Private Attributes
int	istep = 0
	the current step
int	pot_order
	the specified charge extrapolation method
int	rho_extr
	the actually used method
int	nspin
	the number of spins
ModuleBase::Vector3< double > *	dis_old1 = nullptr
	dis_old2 = pos_old1 - pos_old2
ModuleBase::Vector3< double > *	dis_old2 = nullptr
	dis_old1 = pos_now - pos_old1
ModuleBase::Vector3< double > *	dis_now = nullptr
	dis_now = pos_next - pos_now
std::vector< std::vector< double > >	delta_rho1
	the last step difference of rho and atomic_rho
std::vector< std::vector< double > >	delta_rho2
	the second last step difference of rho and atomic_rho
std::vector< std::vector< double > >	delta_rho3
	the third last step difference of rho and atomic_rho
double	alpha
	parameter used in the second order extrapolation
double	beta
	parameter used in the second order extrapolation

Detailed Description

charge extrapolation method

This class implements several charge extrapolation methods: pot_order=0 : copy the old potential (nothing is done); pot_order=1 : subtract old atomic charge density and sum the new if dynamics is done the routine extrapolates also the difference between the scf charge and the atomic one; pot_order=2 : first order extrapolation: [ \rho(t+dt) = 2\ \rho(t)-\rho(t-dt); ] pot_order=3 : second order extrapolation: [ \rho(t+dt) = \rho(t) + \alpha_0\ (\rho(t) - \rho(t-dt))

• \beta_0\ (\rho(t-dt)- \rho(t-2 dt)). ]

The (\alpha_0) and (\beta_0) parameters are calculated in find_alpha_and_beta() so that (|\tau'-\tau(t+dt)|) is minimum. (\tau') and (\tau(t+dt)) are respectively the atomic positions at time t+dt and the extrapolated one: [ \tau(t+dt) = \tau(t) + \alpha_0\ ( \tau(t) - \tau(t-dt) )

• \beta_0\ ( \tau(t-dt) - \tau(t-2 dt) ). ]

Constructor & Destructor Documentation

Charge_Extra()

Charge_Extra::Charge_Extra

(

)

~Charge_Extra()

Charge_Extra::~Charge_Extra

(

)

Member Function Documentation

extrapolate_charge()

void Charge_Extra::extrapolate_charge	(	Parallel_Grid *	Pgrid,
		UnitCell &	ucell,
		Charge *	chr,
		Structure_Factor *	sf,
		std::ofstream &	ofs_running,
		std::ofstream &	ofs_warning
	)

charge extrapolation method

Parameters

Pgrid	parallel grids
ucell	the cell information
chr	the charge density
sf	the structure factor
ofs_running	the output stream
ofs_warning	the output stream

Here is the call graph for this function:

Here is the caller graph for this function:

find_alpha_and_beta()

void Charge_Extra::find_alpha_and_beta ( const int &  natom, std::ofstream &  ofs_running, std::ofstream &  ofs_warning  )

private

determine alpha and beta

Parameters

natom	the number of atoms
ofs_running	the output stream
ofs_warning	the output stream

Here is the call graph for this function:

Here is the caller graph for this function:

Init_CE()

void Charge_Extra::Init_CE	(	const int &	nspin,
		const int &	natom,
		const int &	nrxx,
		const std::string	chg_extrap
	)

Initialization of viriables used in charge extrapolation methods.

When Esolver is initialized, ucell.natom is not determined As a result, data structures in Charge_Extra cannot be allocated This is a temporary solution by delaying the allocation But after ucell and Esolver are fully decoupled Init_CE will be removed and everything put back in the constructor

Parameters

nspin	the number of spins
natom	the number of atoms
nrxx	the number of grids
chg_extrap	the charge extrapolation method

Here is the call graph for this function:

Here is the caller graph for this function:

update_all_dis()

void Charge_Extra::update_all_dis

(

const UnitCell &

ucell

)

update displacements

In the second order extrapolation, the displacements of previous three steps are needed to determine alpha and beta, which are parameters used in this method.

Parameters

ucell

the cell information

Here is the caller graph for this function:

update_delta_rho()

void Charge_Extra::update_delta_rho	(	const UnitCell &	ucell,
		const Charge *	chr,
		const Structure_Factor *	sf
	)

update the difference of charge density

Parameters

ucell	the cell information
chr	the charge density
sf	the structure factor

Here is the call graph for this function:

Here is the caller graph for this function:

Member Data Documentation

alpha

double Charge_Extra::alpha

private

parameter used in the second order extrapolation

beta

double Charge_Extra::beta

private

parameter used in the second order extrapolation

delta_rho1

std::vector<std::vector<double> > Charge_Extra::delta_rho1

private

the last step difference of rho and atomic_rho

delta_rho2

std::vector<std::vector<double> > Charge_Extra::delta_rho2

private

the second last step difference of rho and atomic_rho

delta_rho3

std::vector<std::vector<double> > Charge_Extra::delta_rho3

private

the third last step difference of rho and atomic_rho

dis_now

ModuleBase::Vector3<double>* Charge_Extra::dis_now = nullptr

private

dis_now = pos_next - pos_now

dis_old1

ModuleBase::Vector3<double>* Charge_Extra::dis_old1 = nullptr

private

dis_old2 = pos_old1 - pos_old2

dis_old2

ModuleBase::Vector3<double>* Charge_Extra::dis_old2 = nullptr

private

dis_old1 = pos_now - pos_old1

istep

int Charge_Extra::istep = 0

private

the current step

nspin

int Charge_Extra::nspin

private

the number of spins

pot_order

int Charge_Extra::pot_order

private

the specified charge extrapolation method

rho_extr

int Charge_Extra::rho_extr

private

the actually used method

---

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

• /home/runner/work/abacus-develop/abacus-develop/source/source_estate/module_charge/charge_extra.h
• /home/runner/work/abacus-develop/abacus-develop/source/source_estate/module_charge/charge_extra.cpp