lammps/lib/atc/SchrodingerSolver.cpp

954 lines
34 KiB
C++

// ATC Headers
#include "SchrodingerSolver.h"
#include "ATC_Error.h"
#include "ATC_Coupling.h"
#include "LammpsInterface.h"
#include "PrescribedDataManager.h"
#include "PhysicsModel.h"
#include "LinearSolver.h"
#include "PoissonSolver.h"
#include "Utility.h"
#include <utility>
using std::pair;
using std::set;
using std::stringstream;
using std::min;
using ATC_Utility::to_string;
using ATC_Utility::sgn;
const double zero_tol = 1.e-12;
const double f_tol = 1.e-8;
namespace ATC {
enum oneDconservationEnum {ONED_DENSITY=0, ONED_FLUX, ONED_GLOBAL_FLUX};
double fermi_dirac(const double E, const double T)
{
double f = 1.0;
if (T > 0) f = 1.0 / ( exp(E/(kBeV_*T))+1.0 );
else if (E > 0) f = 0;
return f;
};
//========================================================
// Schrodinger solve
//========================================================
SchrodingerSolver::SchrodingerSolver(
const FieldName fieldName,
const PhysicsModel * physicsModel,
const FE_Engine * feEngine,
const PrescribedDataManager * prescribedDataMgr,
/*const*/ ATC_Coupling * atc,
bool parallel
)
: atc_(atc),
feEngine_(feEngine),
prescribedDataMgr_(prescribedDataMgr),
physicsModel_(physicsModel),
fieldName_(fieldName),
nNodes_(atc->num_nodes()),
parallel_(parallel)
{
}
//-----------------------------------------------------
void SchrodingerSolver::initialize()
{
SPAR_MAT sparseM;
atc_->fe_engine()->compute_mass_matrix(sparseM);
M_ = sparseM.dense_copy();
}
//-----------------------------------------------------
bool SchrodingerSolver::solve(FIELDS & /* fields */)
{
// typedef struct{float real, imag;} COMPLEX;
SPAR_MAT stiffness_;
Array2D <bool> rhsMask(NUM_FIELDS,NUM_FLUX);
rhsMask = false;
rhsMask(ELECTRON_WAVEFUNCTION,FLUX) = true;
rhsMask(ELECTRON_WAVEFUNCTION,SOURCE) = true;
pair<FieldName,FieldName> row_col(ELECTRON_WAVEFUNCTION,
ELECTRON_WAVEFUNCTION);
//set_fixed_nodes();
atc_->fe_engine()->compute_tangent_matrix(
rhsMask, row_col, atc_->fields(), physicsModel_,
atc_->element_to_material_map(), stiffness_);
DENS_MAT K(stiffness_.dense_copy());
set<int> fixedNodes = prescribedDataMgr_->fixed_nodes(ELECTRON_WAVEFUNCTION);
const BC_SET & bcs
= (prescribedDataMgr_->bcs(ELECTRON_WAVEFUNCTION))[0];
DENS_MAT & psi = (atc_->field(ELECTRON_WAVEFUNCTION)).set_quantity();
DENS_MAT & eVecs = (atc_->field(ELECTRON_WAVEFUNCTIONS)).set_quantity();
DENS_MAT & eVals = (atc_->field(ELECTRON_WAVEFUNCTION_ENERGIES)).set_quantity();
if (prescribedDataMgr_->all_fixed(ELECTRON_WAVEFUNCTION)) {
ATC::LammpsInterface::instance()->print_msg("all wavefunctions fixed");
psi.reset(nNodes_,1);
eVecs.reset(nNodes_,1);
eVals.reset(nNodes_,1);
return true;
}
// (1) Helmholtz solve for inhomongeneous bcs
LinearSolver helmholtzSolver_(K,bcs,LinearSolver::AUTO_SOLVE,-1,parallel_);
psi.reset(nNodes_,1);
// (2) Eigenvalue solve
helmholtzSolver_.eigen_system(eVals,eVecs,&M_);
return true;
}
//========================================================
// Schrodinger solve on slices
//========================================================
SliceSchrodingerSolver::SliceSchrodingerSolver(
const FieldName fieldName,
const PhysicsModel * physicsModel,
const FE_Engine * feEngine,
const PrescribedDataManager * prescribedDataMgr,
/*const*/ ATC_Coupling * atc,
const Array< set<int> > & oneDslices,
const Array< double > & oneDdxs,
bool parallel
)
: SchrodingerSolver(fieldName, physicsModel, feEngine, prescribedDataMgr,
atc, parallel),
oneDslices_(oneDslices),
oneDdxs_(oneDdxs)
{}
//--------------------------------------------------------
void SliceSchrodingerSolver::initialize()
{
SchrodingerSolver::initialize();
}
//--------------------------------------------------------
// compute charge density per slice
//--------------------------------------------------------
bool SliceSchrodingerSolver::solve(FIELDS & /* fields */)
{
// fields
DENS_MAT & psi = (atc_->field(ELECTRON_WAVEFUNCTION)).set_quantity();
DENS_MAT & eVecs = (atc_->field(ELECTRON_WAVEFUNCTIONS)).set_quantity();
DENS_MAT & eVals = (atc_->field(ELECTRON_WAVEFUNCTION_ENERGIES)).set_quantity();
psi.reset(nNodes_,1);
eVecs.reset(nNodes_,nNodes_);
eVals.reset(nNodes_,1);
DENS_MAT & Ef = (atc_->field(FERMI_ENERGY)).set_quantity();
DENS_MAT & n = (atc_->field(ELECTRON_DENSITY)).set_quantity();
DENS_MAT & T = (atc_->field(ELECTRON_TEMPERATURE)).set_quantity();
// stiffness = K + V M
SPAR_MAT stiffness_;
Array2D <bool> rhsMask(NUM_FIELDS,NUM_FLUX);
rhsMask = false;
rhsMask(ELECTRON_WAVEFUNCTION,FLUX) = true;
rhsMask(ELECTRON_WAVEFUNCTION,SOURCE) = true;
pair<FieldName,FieldName> row_col(ELECTRON_WAVEFUNCTION,
ELECTRON_WAVEFUNCTION);
atc_->fe_engine()->compute_tangent_matrix(
rhsMask, row_col, atc_->fields(), physicsModel_,
atc_->element_to_material_map(), stiffness_);
DENS_MAT K(stiffness_.dense_copy());
// Eigenvalue solve
DENS_MAT K1,M1;
int nslices = oneDslices_.size();
DENS_MAT b ;
DENS_MAT evals1,evecs1 ;
DENS_MAT n1 ;
BCS bcs;
set <int> one;
one.insert(0);
set <int> eindex;
int iEVal = 0;
for (int islice = 0; islice < nslices ; islice++) {
set<int> & slice = oneDslices_(islice);
int snodes = slice.size();
prescribedDataMgr_->bcs(ELECTRON_WAVEFUNCTION,slice,bcs,true);
const BC_SET & bc = bcs[0];
int nfixed = bc.size();
if (nfixed != snodes) {
// A: solve for e-values and wavefunctions
K.map(slice,slice,K1);
M_.map(slice,slice,M1);
LinearSolver eigensolver(K1,bc,LinearSolver::AUTO_SOLVE,-1);
// wave functions
evals1.reset(snodes,1);
evecs1.reset(snodes,snodes);
eigensolver.eigen_system(evals1,evecs1,&M1);
eindex.clear();
for (int j = 0; j < snodes; j++) eindex.insert(iEVal++);
eVals.insert(eindex,one, evals1);
eindex.clear();
for (int j = 0; j < snodes; j++) eindex.insert(j);
eVecs.insert(slice,eindex,evecs1);
// slice charge density
n1.reset(snodes,1);
set<int>::const_iterator iset;
double aveE_f = 0;
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
aveE_f += Ef(gnode,0);
}
aveE_f /= snodes;
//#define VERBOSE
#ifdef VERBOSE
stringstream ss;
ss << " slice "+to_string(islice+1)+" E_f "+to_string(aveE_f) << "\n"
<< "#-----------------------------------------------\n"
<< "# E-Ef f psi n\n"
<< "#-----------------------------------------------\n";
#endif
// B: compute charge density on slice
int node = 0;
for (iset = slice.begin(); iset != slice.end(); iset++) { // node
int gnode = *iset;
double temp = T(gnode,0);
for (int mode = 0; mode < snodes-nfixed; mode++) {
double Ei = evals1(mode,0);
double E = Ei-aveE_f;
double f = fermi_dirac(E,temp);
double psi1 = evecs1(node,mode); // 2nd index corresp to evals order
#ifdef VERBOSE
ss << node<<":"<<mode << " " << to_string(6,E) << " " << to_string(6,f) << " " << to_string(6,psi1) << " " << to_string(6,n1(node,0)+psi1*psi1*f) << "\n";
#endif
if (f < f_tol) break; // take advantage of E ordering
n1(node,0) += psi1*psi1*f;
}
node++;
}
#ifdef VERBOSE
ATC::LammpsInterface::instance()->print_msg_once(ss.str());
#endif
n.insert(slice,one, n1); // note not "assemble"
}
}
return true;
}
//========================================================
// Schrodinger-Poisson Manager
//========================================================
SchrodingerPoissonManager::SchrodingerPoissonManager() :
maxConsistencyIter_(0),
maxConstraintIter_(0),
oneD_(false),
oneDconserve_(ONED_FLUX),
Ef_shift_(0.),
safe_dEf_(0.),
tol_(1.e-10),
mu_(1.),D_(0.)
{
}
//----------------------------------------------------------
bool SchrodingerPoissonManager::modify(int /* narg */, char **arg)
{
bool match = false;
int argIndx = 0;
if (strcmp(arg[argIndx],"self_consistency")==0) {
argIndx++;
maxConsistencyIter_ = atoi(arg[argIndx]);
match = true;
}
else if (strcmp(arg[argIndx],"conserve")==0) {
oneD_ = true;
argIndx++;
if (strcmp(arg[argIndx],"density")==0) oneDconserve_ = ONED_DENSITY;
else if (strcmp(arg[argIndx],"flux")==0) oneDconserve_ = ONED_FLUX;
else oneDconserve_ = ONED_GLOBAL_FLUX;
argIndx++;
maxConstraintIter_ = atoi(arg[argIndx]);
match = true;
}
else if (strcmp(arg[argIndx],"initial_fermi_level")==0) {
argIndx++;
Ef_shift_ = atof(arg[argIndx]);
match = true;
}
else if (strcmp(arg[argIndx],"safe_fermi_increment")==0) {
argIndx++;
safe_dEf_ = atof(arg[argIndx]);
match = true;
}
else if (strcmp(arg[argIndx],"relaxation")==0) {
argIndx++;
alpha_ = atof(arg[argIndx]);
match = true;
}
else if (strcmp(arg[argIndx],"tolerance")==0) {
argIndx++;
tol_ = atof(arg[argIndx]);
match = true;
}
else if (strcmp(arg[argIndx],"mobility")==0) {
argIndx++;
mu_ = atof(arg[argIndx]);
match = true;
}
else if (strcmp(arg[argIndx],"diffusivity")==0) {
argIndx++;
D_ = atof(arg[argIndx]);
match = true;
}
return match;
}
//----------------------------------------------------------------
SchrodingerPoissonSolver * SchrodingerPoissonManager::initialize(
/*const*/ ATC_Coupling * atc,
SchrodingerSolver * schrodingerSolver,
PoissonSolver * poissonSolver,
const PhysicsModel * physicsModel
)
{
SchrodingerPoissonSolver * ptr;
if (oneD_) {
if (oneDconserve_ == ONED_GLOBAL_FLUX) {
ptr = new GlobalSliceSchrodingerPoissonSolver(atc,
schrodingerSolver,poissonSolver,physicsModel,maxConsistencyIter_,
maxConstraintIter_, oneDconserve_, Ef_shift_, alpha_, safe_dEf_, tol_,
mu_,D_);
}
else {
ptr = new SliceSchrodingerPoissonSolver(atc,
schrodingerSolver,poissonSolver,physicsModel,maxConsistencyIter_,
maxConstraintIter_, oneDconserve_, Ef_shift_, safe_dEf_);
}
}
else {
ptr = new SchrodingerPoissonSolver(atc,
schrodingerSolver,poissonSolver,physicsModel,maxConsistencyIter_);
}
return ptr;
}
//===================================================================
// SchrodingerPoissonSolver
//===================================================================
SchrodingerPoissonSolver::SchrodingerPoissonSolver(
/*const*/ ATC_Coupling * atc,
SchrodingerSolver * schrodingerSolver,
PoissonSolver * poissonSolver,
const PhysicsModel * physicsModel,
int maxConsistencyIter
) :
atc_(atc),
schrodingerSolver_(schrodingerSolver),
poissonSolver_(poissonSolver),
physicsModel_(physicsModel),
maxConsistencyIter_(maxConsistencyIter),
nNodes_(atc_->num_nodes())
{
}
//----------------------------------------------------------------------
void SchrodingerPoissonSolver::solve(FIELDS & rhs, GRAD_FIELD_MATS & /* fluxes */)
{
if ((atc_->prescribed_data_manager()->all_fixed(ELECTRON_WAVEFUNCTION))
&& (atc_->prescribed_data_manager()->all_fixed(ELECTRIC_POTENTIAL))) {
return;
}
double norm = 1.0, norm0 = 1.0; // normPrev = 1.0;
DENS_MAT nPrev,psiPrev,phiPrev;
DENS_MAT & psi = (atc_->field(ELECTRON_WAVEFUNCTIONS)).set_quantity();
DENS_MAT & phi = (atc_->field(ELECTRIC_POTENTIAL)).set_quantity();
DENS_MAT & E_I = (atc_->field(ELECTRON_WAVEFUNCTION_ENERGIES)).set_quantity();
DENS_MAT & Te = (atc_->field(ELECTRON_TEMPERATURE)).set_quantity();
atc_->set_fixed_nodes();
DENS_MAT Te0 = Te; // save
const double tol = 1.e-4;
int k = 0;
double logRatio = 3;
int maxIter = (int) logRatio;
double base = 2.0;
// temperature relaxation loop
for (int i = 0; i < maxIter ; ++i) {
//double alpha = ((double) i) /( (double) maxIter-1);
//double beta = 0.1;
//alpha = (exp(beta*i)-1.0)/(exp(beta*(maxIter-1))-1.0);
double alpha = pow(base,logRatio-i-1);
// self consistency loop
int j = 0; // for storage of last iterate
for (j = 0; j < maxConsistencyIter_ ; ++j) {
// compute eigen-values and vectors
atc_->set_fixed_nodes();
Te = alpha*Te0;
schrodingerSolver_->solve(atc_->fields());
for (int l = 0; l < nNodes_; l++) {
int count = 0;
double T_e = Te(l,0);
for (int m = 0; m < nNodes_; m++) {
double f = fermi_dirac(E_I(m,0), T_e);
if (f > tol) count++;
}
}
// compute charge density
DENS_MAN & n = atc_->field(ELECTRON_DENSITY);
//(n.quantity()).print("DENSITY");
atc_->nodal_projection(ELECTRON_DENSITY,physicsModel_,n);
atc_->set_fixed_nodes();
// solve poisson eqn for electric potential
atc_->set_fixed_nodes();
Te = alpha*Te0;
poissonSolver_->solve(atc_->fields(),rhs);
//DENS_MAT dn = n;
//DENS_MAT dpsi = psi;
//DENS_MAT dphi = phi;
if (i == 0 && j==0) {
nPrev = n.quantity();
psiPrev = psi;
phiPrev = phi;
}
//dn -= nPrev;
//dpsi -= psiPrev;
//dphi -= phiPrev;
norm = (n.quantity()-nPrev).norm();
if (i == 0 && j==0) norm0 = (n.quantity()).norm();
//normPrev = norm;
//psi_normPrev = psi_norm;
//phi_normPrev = phi_norm;
nPrev = n.quantity();
psiPrev = psi;
phiPrev = phi;
k++;
if (j > 0 && norm <= tol*norm0) break;
}
// Tmax_ *= 0.5;
}
}
//===================================================================
// SliceSchrodingerPoissonSolver
//===================================================================
SliceSchrodingerPoissonSolver::SliceSchrodingerPoissonSolver(
/*const*/ ATC_Coupling * atc,
SchrodingerSolver * schrodingerSolver,
PoissonSolver * poissonSolver,
const PhysicsModel * physicsModel,
int maxConsistencyIter,
int maxConstraintIter,
int oneDconserve,
double Ef_shift,
double safe_dEf
) :
SchrodingerPoissonSolver(atc,schrodingerSolver,poissonSolver,physicsModel,maxConsistencyIter),
oneDconserve_(oneDconserve),
oneDcoor_(0),
oneDslices_(((SliceSchrodingerSolver *) schrodingerSolver_)->slices()),
oneDdxs_(((SliceSchrodingerSolver *) schrodingerSolver_)->dxs())
{
Ef_shift_=Ef_shift;
safe_dEf_=safe_dEf;
maxConstraintIter_=maxConstraintIter;
EfHistory_.reset(oneDslices_.size(),2);
}
//--------------------------------------------------------------------------
void SliceSchrodingerPoissonSolver::solve(FIELDS & rhs, GRAD_FIELD_MATS & fluxes)
{
const double tol = 1.e-4; // tolerance on consistency & constraint
double norm = 1.0, norm0 = 1.0;
DENS_MAT nPrev;
DENS_MAT & n = (atc_->field(ELECTRON_DENSITY)).set_quantity();
DENS_MAT & phi = (atc_->field(ELECTRIC_POTENTIAL)).set_quantity();
// fermi energy
DENS_MAT & Ef = (atc_->field(FERMI_ENERGY)).set_quantity();
Ef.reset(nNodes_,1);
int nslices = oneDslices_.size();
Array2D<double> nHistory(nslices,2);
// target for constraint
double target = 0.0;
set<int> & slice = oneDslices_(0); // note assume first slice is fixed
if (oneDconserve_ == ONED_FLUX) atc_->set_sources();
DENS_MAT & nSource = (atc_->source(ELECTRON_DENSITY)).set_quantity();
for (set<int>::const_iterator iset = slice.begin(); iset != slice.end(); iset++) {
if (oneDconserve_ == ONED_FLUX) target += nSource(*iset,0);
else target += n(*iset,0);
}
target /= slice.size();
#ifdef VERBOSE
if (oneDconserve_ == ONED_FLUX) {
if (target > 0) ATC::LammpsInterface::instance()->print_msg_once(" influx target "+ to_string(target));
else ATC::LammpsInterface::instance()->print_msg_once(" efflux target "+ to_string(target));
}
#endif
// A: self consistency loop between Phi and n(psi_i)
double error = 1.0;
for (int i = 0; i < maxConsistencyIter_ ; ++i) {
atc_->set_fixed_nodes();
if (! atc_->prescribedDataMgr_->all_fixed(ELECTRIC_POTENTIAL) )
poissonSolver_->solve(atc_->fields(),rhs);
if (! atc_->prescribedDataMgr_->all_fixed(ELECTRON_DENSITY) ) {
// iterate on Ef
//if (i==0) Ef = -1.0*phi;// E ~ -|e| \Phi, charge of electron e = 1
Ef = -1.0*phi;
Ef +=Ef_shift_;
// B: conservation constraint
for (int j = 0; j < maxConstraintIter_ ; ++j) {
schrodingerSolver_->solve(atc_->fields()); // n(E_f)
atc_->set_fixed_nodes();
error = update_fermi_energy(target,(j==0),fluxes);// root finder
#ifdef VERBOSE
ATC::LammpsInterface::instance()->print_msg_once(to_string(i)+":"+to_string(j)+" constraint_error "+to_string(error)+" / "+to_string(tol*target)+"\n");
#endif
// exit condition based on constraint satisfaction
if (error < tol*fabs(target)) break;
} // loop j : flux constraint
// error based on change in field (Cauchy convergence)
if (i == 0) {
norm = norm0 = n.norm();
}
else {
DENS_MAT dn = n;
dn -= nPrev;
norm = dn.norm();
}
nPrev = n;
#ifdef VERBOSE
#if 0
if (i > 0) ATC::LammpsInterface::instance()->print_msg_once(to_string(i)+" density_change: "+to_string(norm)+" / "+to_string(norm0));
else ATC::LammpsInterface::instance()->print_msg_once("initial norm "+to_string(norm));
#endif
#endif
if (i > 0 && norm <= tol*norm0 && error < tol) break;
}
} // loop i : self consistency
}
//--------------------------------------------------------
// update fermi energy
//--------------------------------------------------------
double SliceSchrodingerPoissonSolver::update_fermi_energy
(double target, bool first, GRAD_FIELD_MATS & fluxes)
{
DENS_MAT & Ef = (atc_->field(FERMI_ENERGY)).set_quantity();
DENS_MAT & n = (atc_->field(ELECTRON_DENSITY)).set_quantity();
DENS_MAT & phi = (atc_->field(ELECTRIC_POTENTIAL)).set_quantity();
const DENS_MAT * y = &n;
if (oneDconserve_ == ONED_FLUX) { // compute J_x
Array2D <bool> rhsMask(NUM_FIELDS,NUM_FLUX); rhsMask = false;
rhsMask(ELECTRON_DENSITY,FLUX) = true;
//#define WIP_REJ
atc_->compute_flux(rhsMask,atc_->fields_,fluxes,physicsModel_);
y = & ( fluxes[ELECTRON_DENSITY][oneDcoor_] );
}
BCS bcs;
double error = 0;
// slice
for (int islice = 0; islice < oneDslices_.size(); islice++) {
#ifdef VERBOSE
std::string cStr(" conserved ");
std::string Estr(" Ef");
#endif
set<int> & slice = oneDslices_(islice);
int nSlice = slice.size();
atc_->prescribedDataMgr_->bcs(ELECTRON_WAVEFUNCTION,slice,bcs,true);
const BC_SET & bc = bcs[0];
int nFixed = bc.size();
if (nFixed == nSlice) continue; // skip if all fixed
double Y = 0.0, X = 0.0;
double nAve = 0., phiAve = 0.;
for (set<int>::const_iterator iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
X += Ef(gnode,0);
Y += (*y)(gnode,0);
nAve += n(gnode,0);
phiAve += phi(gnode,0);
}
X /= nSlice;
Y /= nSlice;
nAve /= nSlice;
phiAve /= nSlice;
// now adjust Ef for each slice
double dY = Y - EfHistory_(islice,0);
double dX = X - EfHistory_(islice,1);
double err = target - Y;
if (target*Y < -zero_tol*target) {
#ifdef VERBOSE
cStr = " opp. SIGNS";
#else
ATC::LammpsInterface::instance()->print_msg_once("WARNING: slice "+to_string(islice)+" target and quantity opposite signs "+to_string(Y));
#endif
}
error += fabs(err);
double dEf = 0.;
if (first) {
dEf = (err < 0) ? -safe_dEf_ : safe_dEf_;
}
else {
if (fabs(dY) < zero_tol*dX) throw ATC_Error("zero increment in conserved field on slice:"+to_string(islice));
dEf = err / dY * dX;
if (fabs(dEf) > safe_dEf_) {
dEf = safe_dEf_* dEf / fabs(dEf);
#ifdef VERBOSE
Estr = " !!";
#else
ATC::LammpsInterface::instance()->print_msg_once("WARNING: slice "+to_string(islice)+ " large Delta E_f "+to_string(dEf));
#endif
}
}
for (set<int>::const_iterator iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
Ef(gnode,0) += dEf;
}
EfHistory_(islice,0) = Y;
EfHistory_(islice,1) = X;
if ( std::isnan(Y) ) throw ATC_Error("target on slice is not a number");
#ifdef VERBOSE
ATC::LammpsInterface::instance()->print_msg_once(" slice"+to_string(islice,2) +cStr+to_string(4,Y/target) +Estr+to_string(4,X)+" n"+to_string(5,nAve)+" phi"+to_string(4,phiAve));
//ATC::LammpsInterface::instance()->print_msg_once(" slice "+to_string(islice) +cStr+to_string(4,Y/target) +" E_f"+to_string(4,X)+dEstr+to_string(4,X-EfHistory_(std::max(0,islice-1),1))+" n"+to_string(4,nAve)+" phi"+to_string(4,phiAve)+" "+to_string(nFixed)+" dn "+to_string(4,dnAve)+" dphi "+to_string(4,dphiAve));
#endif
} // loop slice
return error;
}
//===================================================================
// GlobalSliceSchrodingerPoissonSolver
//===================================================================
GlobalSliceSchrodingerPoissonSolver::GlobalSliceSchrodingerPoissonSolver(
/*const*/ ATC_Coupling * atc,
SchrodingerSolver * schrodingerSolver,
PoissonSolver * poissonSolver,
const PhysicsModel * physicsModel,
int maxConsistencyIter,
int maxConstraintIter,
int oneDconserve,
double Ef0,
double alpha,
double safe_dEf,
double tol,
double mu, double D
) :
SliceSchrodingerPoissonSolver(atc,schrodingerSolver,poissonSolver,physicsModel,maxConsistencyIter,maxConstraintIter,oneDconserve,0,0),
solver_(NULL),
mobility_(mu),diffusivity_(D)
{
Ef0_ = Ef0;
alpha_ = alpha;
safe_dEf_ = safe_dEf;
if (safe_dEf_ < 1.e-20) throw ATC_Error("safe dE_f must be positive");
ATC::LammpsInterface::instance()->print_msg("mobility:"+to_string(mobility_)+" diffusivity:"+to_string(diffusivity_));
tol_ = tol;
nslices_ = oneDslices_.size();
sliceSize_ = (oneDslices_(0)).size();
nNodes_ = nslices_*sliceSize_;
flux_.reset(nNodes_);
J_.reset(nslices_);
//nfixed_ = 2;
nfixed_ = 1;
nfreeSlices_ = nslices_-nfixed_;
nLambda_ = nslices_-1;
lambda_.reset(nLambda_);
dJ_.reset(nLambda_);
F_.reset(nslices_);
Phi_.reset(nslices_);
n_.reset(nslices_);
// form stiffness, lhs dirichlet bc, rhs homogeneous neumann bc
//int m = nfreeSlices_;
int m = nLambda_;
DENS_MAT A(m,m);
for (int i = 1; i < m; ++i) {
A(i,i) = -2;
if (i>0) A(i,i-1) = 1;
if (i<m-1) A(i,i+1) = 1;
}
A(0,0) = -2;
A(0,1) = 1;
A(m-1,m-1) = -2;
A(m-1,m-2) = 1;
//if (nfixed_ == 1) { A(m-1,m-1) = -1; }
double dx = oneDdxs_(0);
A *= 1./dx;
A.print("stiffness",4);
SPAR_MAT K(A);
K_ = K;
// form gradient (account for lhs bc)
int n = nslices_;
DENS_MAT B(m,n);
//for (int i = 0; i < m-1; ++i) {
for (int i = 0; i < m; ++i) {
B(i,i) =-1;
B(i,i+1) = 1; //B(i,i+2) = 1;
}
if (nfixed_ == 1) {
B(m-1,n-2) = -1;
B(m-1,n-1) = 1;
}
B.print("gradient",4);
SPAR_MAT G(B);
G_ = G;
DENS_MAT C(nNodes_,nNodes_);
// local to ATC nodemap: k --> gnode = *iset
int k = 0;
set<int>::const_iterator iset;
for (int islice = 0; islice < nslices_; islice++) {
set<int> & slice = oneDslices_(islice);
for (iset = slice.begin(); iset != slice.end(); iset++) {
double v = 0.5/dx;
if ( k < sliceSize_ || k+1 > (nslices_-1)*sliceSize_ ) v *=2.0;
if (islice > 0) { C(k,k-sliceSize_) += v; }
else { C(k,k) += v; }
if (islice < nslices_-1) { C(k,k+sliceSize_) -= v; }
else { C(k,k) -= v; }
k++;
}
}
//C.print("2D gradient",4);
SPAR_MAT G2(C);
G2_ = G2;
solver_ = new LinearSolver(K_); // for lambda
rhsMask_.reset(NUM_FIELDS,NUM_FLUX); rhsMask_ = false;
rhsMask_(ELECTRON_DENSITY,FLUX) = true;
// report
if (nfixed_ ==2)
ATC::LammpsInterface::instance()->print_msg_once("schrodinger-poisson solver: Dirichlet INLET, Dirichlet; OUTLET");
else if (nfixed_ ==1)
ATC::LammpsInterface::instance()->print_msg_once("schrodinger-poisson solver: Dirichlet INLET, Neumann; OUTLET");
else
ATC_Error("schrodinger-poisson solver:too many fixed");
}
GlobalSliceSchrodingerPoissonSolver::~GlobalSliceSchrodingerPoissonSolver(void) {
if (solver_) delete solver_;
}
//--------------------------------------------------------------------------
void GlobalSliceSchrodingerPoissonSolver::solve(FIELDS & rhs, GRAD_FIELD_MATS & /* fluxes */)
{
const DENS_MAT & phi = (atc_->fields_[ELECTRIC_POTENTIAL]).quantity();
const DENS_MAT & n = (atc_->fields_[ELECTRON_DENSITY] ).quantity();
DENS_MAT & Ef = (atc_->field(FERMI_ENERGY)).set_quantity();
Ef.reset(phi.nRows(),1);
norm_ = norm0_ = 1.0;
for (int i = 0; i < maxConstraintIter_ ; ++i) {
atc_->set_fixed_nodes();
if (! atc_->prescribedDataMgr_->all_fixed(ELECTRIC_POTENTIAL) ) {
poissonSolver_->solve(atc_->fields(),rhs);
}
else {
ATC::LammpsInterface::instance()->print_msg_once("WARNING: phi is fixed");
}
if (i == 0) { report(0); }
if (! atc_->prescribedDataMgr_->all_fixed(ELECTRON_DENSITY) ) {
update_fermi_level(); // update Ef = Ef0 +lambda
schrodingerSolver_->solve(atc_->fields()); // updates n(E_f)
//exponential_electron_density(); // surrogate
compute_flux(n,phi); // compute J(n,phi) & dJ_
solver_->solve(lambda_,dJ_); // conservation constraint
//lambda_.print("lambda");
//lambda_.print("[[J}}");
}
else {
ATC::LammpsInterface::instance()->print_msg_once("WARNING: rho is fixed");
}
norm_ = dJ_.norm();
report(i+1);
if (i == 0 && norm_ > tol_) norm0_ = norm_;
else { if (norm_ < tol_*norm0_) break; }
}
}
//--------------------------------------------------------------------------
void GlobalSliceSchrodingerPoissonSolver::exponential_electron_density()
{
std::cout << "******************HACK******************\n";
DENS_MAT & n = (atc_->fields_[ELECTRON_DENSITY] ).set_quantity();
DENS_MAT & Ef = (atc_->field(FERMI_ENERGY)).set_quantity();
double T = 300;
double n0 = 1.e-2;
set<int>::const_iterator iset;
for (int islice = 0; islice < nslices_; islice++) {
set<int> & slice = oneDslices_(islice);
double aveE_f = 0.0;
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
aveE_f += Ef(gnode,0);
}
aveE_f /= slice.size();
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
//std::cout << phi(gnode,0)+aveE_f << "\n";
//n(gnode,0) = -n0*exp(-(phi(gnode,0)+aveE_f)/(kBeV_*T));
//n(gnode,0) = -n0*exp((-phi(gnode,0))/(kBeV_*T));
//n(gnode,0) = -n0*exp(aveE_f/(kBeV_*T));
//n(gnode,0) = aveE_f+0.01;
//n(gnode,0) = aveE_f;
//n(gnode,0) = phi(gnode,0);
//n(gnode,0) = -n0*(phi(gnode,0)+aveE_f)/(kBeV_*T);
n(gnode,0) = -n0*(aveE_f)/(kBeV_*T);
}
}
}
//--------------------------------------------------------------------------
void GlobalSliceSchrodingerPoissonSolver::report(int i)
{
const DENS_MAT & phi = (atc_->fields_[ELECTRIC_POTENTIAL]).quantity();
const DENS_MAT & n = (atc_->fields_[ELECTRON_DENSITY] ).quantity();
const DENS_MAT & Ef = (atc_->field(FERMI_ENERGY)).quantity();
set<int>::const_iterator iset;
for (int islice = 0; islice < nslices_; islice++) {
set<int> & slice = oneDslices_(islice);
double Phi = 0.0;
double N = 0.0;
double EF = 0.0;
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
Phi += phi(gnode,0);
N += n(gnode,0);
EF += Ef(gnode,0);
}
Phi /= slice.size();
Phi_(islice) = Phi; // average potential
N /= slice.size();
n_(islice) = N; // average electron density
EF /= slice.size();
F_(islice) = EF; // average Fermi level
}
stringstream header;
header << "\n";
header << "#----------------------------------------------------------------------\n";
header << "# [[J]] lambda E_f phi n J\n";
header << "#----------------------------------------------------------------------\n";
if (i == 0) {
ATC::LammpsInterface::instance()->write_file("slice.dat",header.str());
}
stringstream ss;
ss << "\n";
// first slice (fixed E_F)
double dJ0 = J_(1)-J_(0);
ss << to_string(1,2) << "*" << to_string(6,dJ0) << " " << to_string(6,0.) << " " << to_string(6,F_(0)) << " " << to_string(6,Phi_(0)) << " " << to_string(6,n_(0)) << " " << to_string(6,J_(0)) << "\n";
// interior
for (int j = 1; j < nslices_-1; ++j) {
ss << to_string(j+1,2) << " " << to_string(6,dJ_(j-1)) << " " << to_string(6,lambda_(j-1)) << " " << to_string(6,F_(j)) << " " << to_string(6,Phi_(j)) << " " << to_string(6,n_(j)) << " " << to_string(6,J_(j)) << "\n";
}
// last slice (fixed E_F)
double dJn = J_(nslices_-1)-J_(nslices_-2);
int j = nslices_-1;
double lambdaN = 0.;
std::string space = "*";
if (nfixed_ == 1) {
lambdaN = lambda_(nslices_-2);
space = " ";
}
ss << to_string(nslices_,2) << space << to_string(6,dJn) << " " << to_string(6,lambdaN) << " " << to_string(6,F_(j)) << " " << to_string(6,Phi_(j)) << " " << to_string(6,n_(j)) << " " << to_string(6,J_(j)) << "\n";
stringstream is;
is << "\n# iteration: " << to_string(i)+"/ "+to_string(maxConstraintIter_)+" constraint norm:"+to_string(6,norm_/norm0_) << " " << nslices_ << " slices";
ATC::LammpsInterface::instance()->print_msg(is.str()+header.str()+ss.str());
ATC::LammpsInterface::instance()->write_file("slice.dat",ss.str()+is.str()+"\n",std::ofstream::app);
}
//--------------------------------------------------------------------------
void GlobalSliceSchrodingerPoissonSolver::compute_flux(
const DENS_MAT & n, const DENS_MAT & phi)
{
DENS_VEC f(nNodes_);
DENS_VEC gradphi(nNodes_);
DENS_VEC gradn(nNodes_);
int k = 0;
set<int>::const_iterator iset;
// grad phi
for (int islice = 0; islice < nslices_; islice++) {
set<int> & slice = oneDslices_(islice);
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
f(k) = phi(gnode,0);
k++;
}
}
//f.print("phi");
gradphi = G2_*f;
//gradphi.print("grad phi");
k = 0;
// grad n
for (int islice = 0; islice < nslices_; islice++) {
set<int> & slice = oneDslices_(islice);
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
f(k) = n(gnode,0);
k++;
}
}
//f.print("n");
gradn = G2_*f;
////gradn.print("grad n");
flux_.reset(nNodes_);
for (k = 0; k < nNodes_; k++) {
flux_(k) = -mobility_*f(k)*gradphi(k)-diffusivity_*gradn(k);
}
//flux_.print("flux");
// per slice flux and diference
k = 0;
for (int islice = 0; islice < nslices_; islice++) {
set<int> & slice = oneDslices_(islice);
J_(islice) = 0;
for (iset = slice.begin(); iset != slice.end(); iset++) {
J_(islice) += flux_(k);
k++;
}
J_(islice) /= slice.size();
//std::cout << islice << " J " << J_(islice) << "\n";
}
//J_.print("J");
dJ_ = G_*J_;
}
//--------------------------------------------------------------------------
void GlobalSliceSchrodingerPoissonSolver::update_fermi_level()
{
DENS_MAT & Ef = (atc_->field(FERMI_ENERGY) ).set_quantity();
DENS_MAT & phi = (atc_->field(ELECTRIC_POTENTIAL)).set_quantity();
DENS_MAT & n = (atc_->field(ELECTRON_DENSITY) ).set_quantity();
set<int>::const_iterator iset;
for (int islice = 0; islice < nslices_; islice++) {
set<int> & slice = oneDslices_(islice);
double Phi = 0.;
double N = 0.;
//F_(islice) = Ef0_;
if (islice > 0 && islice < nslices_-1) {
F_(islice) += alpha_*lambda_(islice-1);
}
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
Phi += phi(gnode,0);
N += n(gnode,0);
}
Phi /= slice.size();
Phi_(islice) = Phi; // average potential
N /= slice.size();
n_(islice) = N; // average electron density
//F_(j) += min(fabs(alpha_*lambda),safe_dEf_)*sgn(lambda);
for (iset = slice.begin(); iset != slice.end(); iset++) {
int gnode = *iset;
Ef(gnode,0) = F_(islice);
}
}
//Ef.print("Ef");
}
};