double CheMPS2::CASSCF::solve( const int Nelectrons, const int TwoS, const int Irrep, ConvergenceScheme * OptScheme, const int rootNum, DMRGSCFoptions * scf_options ){
const int num_elec = Nelectrons - 2 * iHandler->getNOCCsum();
assert( num_elec >= 0 );
assert(( OptScheme != NULL ) || (( OptScheme == NULL ) && ( rootNum == 1 )));
// Convergence variables
double gradNorm = 1.0;
double updateNorm = 1.0;
double * gradient = new double[ unitary->getNumVariablesX() ];
for ( int cnt = 0; cnt < unitary->getNumVariablesX(); cnt++ ){ gradient[ cnt ] = 0.0; }
double * diis_vec = NULL;
double Energy = 1e8;
// The CheMPS2::Problem for the inner DMRG calculation
Hamiltonian * HamDMRG = new Hamiltonian(nOrbDMRG, SymmInfo.getGroupNumber(), iHandler->getIrrepOfEachDMRGorbital());
Problem * Prob = new Problem(HamDMRG, TwoS, num_elec, Irrep);
Prob->SetupReorderD2h(); //Doesn't matter if the group isn't D2h, Prob checks it.
// Determine the maximum NORB(irrep) and the max_block_size for the ERI orbital rotation
const int maxlinsize = iHandler->getNORBmax();
const long long fullsize = ((long long) maxlinsize ) * ((long long) maxlinsize ) * ((long long) maxlinsize ) * ((long long) maxlinsize );
const string tmp_filename = CheMPS2::defaultTMPpath + "/" + CheMPS2::DMRGSCF_eri_storage_name;
const int dmrgsize_power4 = nOrbDMRG * nOrbDMRG * nOrbDMRG * nOrbDMRG;
//For (ERI rotation, update unitary, block diagonalize, orbital localization)
const int temp_work_size = (( fullsize > CheMPS2::DMRGSCF_max_mem_eri_tfo ) ? CheMPS2::DMRGSCF_max_mem_eri_tfo : fullsize );
const int work_mem_size = max( max( temp_work_size , maxlinsize * maxlinsize * 4 ) , dmrgsize_power4 );
double * mem1 = new double[ work_mem_size ];
double * mem2 = new double[ work_mem_size ];
//The two-body rotator and Edmiston-Ruedenberg active space localizer
EdmistonRuedenberg * theLocalizer = NULL;
if ( scf_options->getWhichActiveSpace() == 2 ){ theLocalizer = new EdmistonRuedenberg( HamDMRG->getVmat(), iHandler->getGroupNumber() ); }
//Load unitary from disk
if ( scf_options->getStoreUnitary() ){
struct stat file_info;
int master_stat = stat( (scf_options->getUnitaryStorageName()).c_str(), &file_info );
if ( master_stat == 0 ){ unitary->loadU( scf_options->getUnitaryStorageName() ); }
}
//Load DIIS from disk
DIIS * diis = NULL;
if (( scf_options->getDoDIIS() ) && ( scf_options->getStoreDIIS() )){
struct stat file_info;
int master_stat = stat( (scf_options->getDIISStorageName()).c_str(), &file_info );
if ( master_stat == 0 ){
const int diis_vec_size = iHandler->getROTparamsize();
diis = new DIIS( diis_vec_size, unitary->getNumVariablesX(), scf_options->getNumDIISVecs() );
diis->loadDIIS( scf_options->getDIISStorageName() );
diis_vec = new double[ diis_vec_size ];
}
}
int nIterations = 0;
/*******************************
*** Actual DMRGSCF loops ***
*******************************/
while (( gradNorm > scf_options->getGradientThreshold() ) && ( nIterations < scf_options->getMaxIterations() )){
nIterations++;
//Update the unitary transformation
if ( unitary->getNumVariablesX() > 0 ){
unitary->updateUnitary( mem1, mem2, gradient, true, true ); //multiply = compact = true
if (( scf_options->getDoDIIS() ) && ( updateNorm <= scf_options->getDIISGradientBranch() )){
if ( scf_options->getWhichActiveSpace() == 1 ){
cout << "DMRGSCF::solve : DIIS has started. Active space not rotated to NOs anymore!" << endl;
}
if ( scf_options->getWhichActiveSpace() == 2 ){
cout << "DMRGSCF::solve : DIIS has started. Active space not rotated to localized orbitals anymore!" << endl;
}
if ( diis == NULL ){
const int diis_vec_size = iHandler->getROTparamsize();
diis = new DIIS( diis_vec_size, unitary->getNumVariablesX(), scf_options->getNumDIISVecs() );
diis_vec = new double[ diis_vec_size ];
unitary->makeSureAllBlocksDetOne( mem1, mem2 );
}
unitary->getLog( diis_vec, mem1, mem2 );
diis->appendNew( gradient, diis_vec );
diis->calculateParam( diis_vec );
unitary->updateUnitary( mem1, mem2, diis_vec, false, false ); //multiply = compact = false
}
}
if (( scf_options->getStoreUnitary() ) && ( gradNorm != 1.0 )){ unitary->saveU( scf_options->getUnitaryStorageName() ); }
if (( scf_options->getStoreDIIS() ) && ( updateNorm != 1.0 ) && ( diis != NULL )){ diis->saveDIIS( scf_options->getDIISStorageName() ); }
int master_diis = (( diis != NULL ) ? 1 : 0 );
//Fill HamDMRG
buildQmatOCC();
buildTmatrix();
fillConstAndTmatDMRG( HamDMRG );
DMRGSCFVmatRotations::rotate( VMAT_ORIG, HamDMRG->getVmat(), NULL, 'A', 'A', 'A', 'A', iHandler, unitary, mem1, mem2, work_mem_size, tmp_filename );
//Localize the active space and reorder the orbitals within each irrep based on the exchange matrix
if (( scf_options->getWhichActiveSpace() == 2 ) && ( master_diis == 0 )){ //When the DIIS has started: stop
theLocalizer->Optimize(mem1, mem2, scf_options->getStartLocRandom()); //Default EDMISTONRUED_gradThreshold and EDMISTONRUED_maxIter used
theLocalizer->FiedlerExchange(maxlinsize, mem1, mem2);
fillLocalizedOrbitalRotations(theLocalizer->getUnitary(), iHandler, mem1);
unitary->rotateActiveSpaceVectors(mem1, mem2);
buildQmatOCC(); //With an updated unitary, the Qocc, Tmat, and HamDMRG objects need to be updated as well.
buildTmatrix();
fillConstAndTmatDMRG( HamDMRG );
DMRGSCFVmatRotations::rotate( VMAT_ORIG, HamDMRG->getVmat(), NULL, 'A', 'A', 'A', 'A', iHandler, unitary, mem1, mem2, work_mem_size, tmp_filename );
cout << "DMRGSCF::solve : Rotated the active space to localized orbitals, sorted according to the exchange matrix." << endl;
}
if (( OptScheme == NULL ) && ( rootNum == 1 )){ // Do FCI, and calculate the 2DM
const int nalpha = ( num_elec + TwoS ) / 2;
const int nbeta = ( num_elec - TwoS ) / 2;
const double workmem = 1000.0; // 1GB
const int verbose = 2;
CheMPS2::FCI * theFCI = new CheMPS2::FCI( HamDMRG, nalpha, nbeta, Irrep, workmem, verbose );
double * inoutput = new double[ theFCI->getVecLength(0) ];
theFCI->ClearVector( theFCI->getVecLength(0), inoutput );
inoutput[ theFCI->LowestEnergyDeterminant() ] = 1.0;
Energy = theFCI->GSDavidson( inoutput );
theFCI->Fill2RDM( inoutput, DMRG2DM );
delete theFCI;
delete [] inoutput;
} else { //Do the DMRG sweeps, and calculate the 2DM
for ( int cnt = 0; cnt < dmrgsize_power4; cnt++ ){ DMRG2DM[ cnt ] = 0.0; } //Clear the 2-RDM (to allow for state-averaged calculations)
DMRG * theDMRG = new DMRG(Prob, OptScheme);
for (int state = 0; state < rootNum; state++){
if (state > 0){ theDMRG->newExcitation( fabs( Energy ) ); }
Energy = theDMRG->Solve();
if ( scf_options->getStateAveraging() ){ // When SA-DMRGSCF: 2DM += current 2DM
theDMRG->calc2DMandCorrelations();
copy2DMover( theDMRG->get2DM(), nOrbDMRG, DMRG2DM );
}
if ((state == 0) && (rootNum > 1)){ theDMRG->activateExcitations( rootNum-1 ); }
}
if ( !( scf_options->getStateAveraging() )){ // When SS-DMRGSCF: 2DM += last 2DM
theDMRG->calc2DMandCorrelations();
copy2DMover( theDMRG->get2DM(), nOrbDMRG, DMRG2DM );
}
if (scf_options->getDumpCorrelations()){ theDMRG->getCorrelations()->Print(); } // Correlations have been calculated in the loop (SA) or outside of the loop (SS)
if (CheMPS2::DMRG_storeMpsOnDisk){ theDMRG->deleteStoredMPS(); }
if (CheMPS2::DMRG_storeRenormOptrOnDisk){ theDMRG->deleteStoredOperators(); }
delete theDMRG;
if ((scf_options->getStateAveraging()) && (rootNum > 1)){
const double averagingfactor = 1.0 / rootNum;
for ( int cnt = 0; cnt < dmrgsize_power4; cnt++ ){ DMRG2DM[ cnt ] *= averagingfactor; }
}
}
setDMRG1DM(num_elec, nOrbDMRG, DMRG1DM, DMRG2DM);
//Possibly rotate the active space to the natural orbitals
if (( scf_options->getWhichActiveSpace() == 1 ) && ( master_diis == 0 )){ //When the DIIS has started: stop
copy_active( DMRG1DM, theQmatWORK, iHandler, true );
block_diagonalize( 'A', theQmatWORK, unitary, mem1, mem2, iHandler, true, DMRG2DM ); // Unitary is updated and DMRG2DM rotated
setDMRG1DM( num_elec, nOrbDMRG, DMRG1DM, DMRG2DM );
buildQmatOCC(); //With an updated unitary, the Qocc and Tmat matrices need to be updated as well.
buildTmatrix();
cout << "DMRGSCF::solve : Rotated the active space to natural orbitals, sorted according to the NOON." << endl;
}
//Calculate the matrix elements needed to calculate the gradient and hessian
buildQmatACT();
DMRGSCFVmatRotations::rotate( VMAT_ORIG, NULL, theRotatedTEI, 'C', 'C', 'F', 'F', iHandler, unitary, mem1, mem2, work_mem_size, tmp_filename );
DMRGSCFVmatRotations::rotate( VMAT_ORIG, NULL, theRotatedTEI, 'C', 'V', 'C', 'V', iHandler, unitary, mem1, mem2, work_mem_size, tmp_filename );
buildFmat( theFmatrix, theTmatrix, theQmatOCC, theQmatACT, iHandler, theRotatedTEI, DMRG2DM, DMRG1DM);
buildWtilde(wmattilde, theTmatrix, theQmatOCC, theQmatACT, iHandler, theRotatedTEI, DMRG2DM, DMRG1DM);
//Calculate the gradient, hessian and corresponding update. On return, gradient contains the rescaled gradient == the update.
augmentedHessianNR(theFmatrix, wmattilde, iHandler, unitary, gradient, &updateNorm, &gradNorm);
}
delete [] mem1;
delete [] mem2;
delete_file( tmp_filename );
delete Prob;
delete HamDMRG;
delete [] gradient;
if ( diis_vec != NULL ){ delete [] diis_vec; }
if ( diis != NULL ){ delete diis; }
if ( theLocalizer != NULL ){ delete theLocalizer; }
return Energy;
}
double CheMPS2::CASSCF::caspt2( const int Nelectrons, const int TwoS, const int Irrep, ConvergenceScheme * OptScheme, const int rootNum, DMRGSCFoptions * scf_options, const double IPEA, const double IMAG, const bool PSEUDOCANONICAL, const bool CHECKPOINT, const bool CUMULANT ){
#ifdef CHEMPS2_MPI_COMPILATION
const bool am_i_master = ( MPIchemps2::mpi_rank() == MPI_CHEMPS2_MASTER );
#else
const bool am_i_master = true;
#endif
const int num_elec = Nelectrons - 2 * iHandler->getNOCCsum();
assert( num_elec >= 0 );
if ( CASPT2::vector_length( iHandler ) == 0 ){
if ( am_i_master ){
cout << "CheMPS2::CASSCF::caspt2 : There are no CASPT2 excitations between the CORE, ACTIVE, and VIRTUAL orbital spaces." << endl;
}
return 0.0;
}
//Determine the maximum NORB(irrep) and the max_block_size for the ERI orbital rotation
const int maxlinsize = iHandler->getNORBmax();
const long long fullsize = ((long long) maxlinsize ) * ((long long) maxlinsize ) * ((long long) maxlinsize ) * ((long long) maxlinsize );
const string tmp_filename = tmp_folder + "/" + CheMPS2::DMRGSCF_eri_storage_name;
const int dmrgsize_power4 = nOrbDMRG * nOrbDMRG * nOrbDMRG * nOrbDMRG;
//For (ERI rotation, update unitary, block diagonalize, orbital localization)
DMRGSCFintegrals * theRotatedTEI = new DMRGSCFintegrals( iHandler );
const int temp_work_size = (( fullsize > CheMPS2::DMRGSCF_max_mem_eri_tfo ) ? CheMPS2::DMRGSCF_max_mem_eri_tfo : fullsize );
const int work_mem_size = max( max( temp_work_size , maxlinsize * maxlinsize * 4 ) , dmrgsize_power4 );
const int tot_dmrg_power6 = dmrgsize_power4 * nOrbDMRG * nOrbDMRG;
double * mem1 = new double[ work_mem_size ];
double * mem2 = new double[ ( PSEUDOCANONICAL ) ? work_mem_size : max( work_mem_size, tot_dmrg_power6 ) ];
// Rotate to pseudocanonical orbitals
if ( PSEUDOCANONICAL ){
assert( successful_solve ); // DMRG1RDM needs to be set by CASSCF::solve for buildQmatACT()
buildTmatrix();
buildQmatOCC();
buildQmatACT();
construct_fock( theFmatrix, theTmatrix, theQmatOCC, theQmatACT, iHandler );
block_diagonalize( 'O', theFmatrix, unitary, mem1, mem2, iHandler, false, NULL, NULL, NULL );
block_diagonalize( 'A', theFmatrix, unitary, mem1, mem2, iHandler, false, NULL, NULL, NULL );
block_diagonalize( 'V', theFmatrix, unitary, mem1, mem2, iHandler, false, NULL, NULL, NULL );
} else {
if ( successful_solve == false ){
assert( scf_options->getStoreUnitary() );
if ( am_i_master ){
struct stat file_info;
const int file_stat = stat( (scf_options->getUnitaryStorageName()).c_str(), &file_info );
assert( file_stat == 0 );
unitary->loadU( scf_options->getUnitaryStorageName() );
}
#ifdef CHEMPS2_MPI_COMPILATION
unitary->broadcast( MPI_CHEMPS2_MASTER );
#endif
}
}
// Fill active space Hamiltonian
Hamiltonian * HamAS = new Hamiltonian( nOrbDMRG, SymmInfo.getGroupNumber(), iHandler->getIrrepOfEachDMRGorbital() );
Problem * Prob = new Problem( HamAS, TwoS, num_elec, Irrep );
Prob->SetupReorderD2h(); // Doesn't matter if the group isn't D2h, Prob checks it.
buildTmatrix();
buildQmatOCC();
fillConstAndTmatDMRG( HamAS );
if ( am_i_master ){
DMRGSCFrotations::rotate( VMAT_ORIG, HamAS->getVmat(), NULL, 'A', 'A', 'A', 'A', iHandler, unitary, mem1, mem2, work_mem_size, tmp_filename );
}
#ifdef CHEMPS2_MPI_COMPILATION
HamAS->getVmat()->broadcast( MPI_CHEMPS2_MASTER );
#endif
double E_CASSCF = 0.0;
double * three_dm = new double[ tot_dmrg_power6 ];
double * contract = new double[ tot_dmrg_power6 ];
for ( int cnt = 0; cnt < tot_dmrg_power6; cnt++ ){ contract[ cnt ] = 0.0; }
int next_hamorb1 = 0;
int next_hamorb2 = 0;
const bool make_checkpt = (( CUMULANT == false ) && ( CHECKPOINT ));
bool checkpt_loaded = false;
if ( make_checkpt ){
assert(( OptScheme != NULL ) || ( rootNum > 1 ));
checkpt_loaded = read_f4rdm_checkpoint( CheMPS2::DMRGSCF_f4rdm_name, &next_hamorb1, &next_hamorb2, tot_dmrg_power6, contract );
}
// Solve the active space problem
if (( OptScheme == NULL ) && ( rootNum == 1 )){ // Do FCI
if ( am_i_master ){
const int nalpha = ( num_elec + TwoS ) / 2;
const int nbeta = ( num_elec - TwoS ) / 2;
const double workmem = 1000.0; // 1GB
const int verbose = 2;
CheMPS2::FCI * theFCI = new CheMPS2::FCI( HamAS, nalpha, nbeta, Irrep, workmem, verbose );
double * inoutput = new double[ theFCI->getVecLength(0) ];
theFCI->ClearVector( theFCI->getVecLength(0), inoutput );
inoutput[ theFCI->LowestEnergyDeterminant() ] = 1.0;
E_CASSCF = theFCI->GSDavidson( inoutput );
theFCI->Fill2RDM( inoutput, DMRG2DM ); // 2-RDM
theFCI->Fill3RDM( inoutput, three_dm ); // 3-RDM
setDMRG1DM( num_elec, nOrbDMRG, DMRG1DM, DMRG2DM ); // 1-RDM
buildQmatACT();
construct_fock( theFmatrix, theTmatrix, theQmatOCC, theQmatACT, iHandler );
copy_active( theFmatrix, mem2, iHandler ); // Fock
theFCI->Fock4RDM( inoutput, three_dm, mem2, contract ); // trace( Fock * 4-RDM )
delete theFCI;
delete [] inoutput;
}
#ifdef CHEMPS2_MPI_COMPILATION
MPIchemps2::broadcast_array_double( &E_CASSCF, 1, MPI_CHEMPS2_MASTER );
MPIchemps2::broadcast_array_double( DMRG2DM, dmrgsize_power4, MPI_CHEMPS2_MASTER );
MPIchemps2::broadcast_array_double( three_dm, tot_dmrg_power6, MPI_CHEMPS2_MASTER );
MPIchemps2::broadcast_array_double( contract, tot_dmrg_power6, MPI_CHEMPS2_MASTER );
setDMRG1DM( num_elec, nOrbDMRG, DMRG1DM, DMRG2DM );
#endif
} else { // Do the DMRG sweeps
assert( OptScheme != NULL );
for ( int cnt = 0; cnt < dmrgsize_power4; cnt++ ){ DMRG2DM[ cnt ] = 0.0; } // Clear the 2-RDM
CheMPS2::DMRG * theDMRG = new DMRG( Prob, OptScheme, make_checkpt, tmp_folder );
for ( int state = 0; state < rootNum; state++ ){
if ( state > 0 ){ theDMRG->newExcitation( fabs( E_CASSCF ) ); }
if ( checkpt_loaded == false ){ E_CASSCF = theDMRG->Solve(); }
if (( state == 0 ) && ( rootNum > 1 )){ theDMRG->activateExcitations( rootNum - 1 ); }
}
theDMRG->calc_rdms_and_correlations( true );
copy2DMover( theDMRG->get2DM(), nOrbDMRG, DMRG2DM ); // 2-RDM
setDMRG1DM( num_elec, nOrbDMRG, DMRG1DM, DMRG2DM ); // 1-RDM
buildQmatACT();
construct_fock( theFmatrix, theTmatrix, theQmatOCC, theQmatACT, iHandler );
copy_active( theFmatrix, mem2, iHandler ); // Fock
if ( CUMULANT ){
CheMPS2::Cumulant::gamma4_fock_contract_ham( Prob, theDMRG->get3DM(), theDMRG->get2DM(), mem2, contract );
} else {
for ( int ham_orbz = 0; ham_orbz < nOrbDMRG; ham_orbz++ ){
if (( next_hamorb1 == ham_orbz ) && ( next_hamorb2 == ham_orbz )){
theDMRG->Symm4RDM( three_dm, ham_orbz, ham_orbz, false );
int size = tot_dmrg_power6;
double f_zz = 0.5 * mem2[ ham_orbz + nOrbDMRG * ham_orbz ];
int inc1 = 1;
daxpy_( &size, &f_zz, three_dm, &inc1, contract, &inc1 ); // trace( Fock * 4-RDM )
if ( ham_orbz == nOrbDMRG - 1 ){
next_hamorb1 = 0;
next_hamorb2 = 1;
} else {
next_hamorb1 = ham_orbz + 1;
next_hamorb2 = ham_orbz + 1;
}
if ( make_checkpt ){ write_f4rdm_checkpoint( CheMPS2::DMRGSCF_f4rdm_name, &next_hamorb1, &next_hamorb2, tot_dmrg_power6, contract ); }
}
}
if ( PSEUDOCANONICAL == false ){
for ( int ham_orb1 = 0; ham_orb1 < nOrbDMRG; ham_orb1++ ){
for ( int ham_orb2 = ham_orb1 + 1; ham_orb2 < nOrbDMRG; ham_orb2++ ){
if (( next_hamorb1 == ham_orb1 ) && ( next_hamorb2 == ham_orb2 )){
if ( HamAS->getOrbitalIrrep( ham_orb1 ) == HamAS->getOrbitalIrrep( ham_orb2 ) ){
theDMRG->Symm4RDM( three_dm, ham_orb1, ham_orb2, false );
int size = tot_dmrg_power6;
double f_12 = 0.5 * ( mem2[ ham_orb1 + nOrbDMRG * ham_orb2 ] + mem2[ ham_orb2 + nOrbDMRG * ham_orb1 ] );
int inc1 = 1;
daxpy_( &size, &f_12, three_dm, &inc1, contract, &inc1 ); // trace( Fock * 4-RDM )
}
if ( ham_orb2 == nOrbDMRG - 1 ){
next_hamorb1 = next_hamorb1 + 1;
next_hamorb2 = next_hamorb1 + 1;
} else {
next_hamorb2 = next_hamorb2 + 1;
}
if (( HamAS->getOrbitalIrrep( ham_orb1 ) == HamAS->getOrbitalIrrep( ham_orb2 ) ) && ( make_checkpt )){
write_f4rdm_checkpoint( CheMPS2::DMRGSCF_f4rdm_name, &next_hamorb1, &next_hamorb2, tot_dmrg_power6, contract );
}
}
}
}
}
}
theDMRG->get3DM()->fill_ham_index( 1.0, false, three_dm, 0, nOrbDMRG );
if (( CheMPS2::DMRG_storeMpsOnDisk ) && ( make_checkpt == false )){ theDMRG->deleteStoredMPS(); }
if ( CheMPS2::DMRG_storeRenormOptrOnDisk ){ theDMRG->deleteStoredOperators(); }
delete theDMRG;
}
delete Prob;
delete HamAS;
if ( PSEUDOCANONICAL == false ){
if ( am_i_master ){ cout << "CASPT2 : Deviation from pseudocanonical = " << deviation_from_blockdiag( theFmatrix, iHandler ) << endl; }
block_diagonalize( 'O', theFmatrix, unitary, mem1, mem2, iHandler, false, NULL, NULL, NULL );
block_diagonalize( 'A', theFmatrix, unitary, mem1, mem2, iHandler, false, DMRG2DM, three_dm, contract ); // 2-RDM, 3-RDM, and trace( Fock * cu(4)-4-RDM )
block_diagonalize( 'V', theFmatrix, unitary, mem1, mem2, iHandler, false, NULL, NULL, NULL );
setDMRG1DM( num_elec, nOrbDMRG, DMRG1DM, DMRG2DM ); // 1-RDM
buildTmatrix();
buildQmatOCC();
buildQmatACT();
construct_fock( theFmatrix, theTmatrix, theQmatOCC, theQmatACT, iHandler ); // Fock
}
// Calculate the matrix elements needed to calculate the CASPT2 V-vector
if ( am_i_master ){
DMRGSCFrotations::rotate( VMAT_ORIG, NULL, theRotatedTEI, 'C', 'C', 'F', 'F', iHandler, unitary, mem1, mem2, work_mem_size, tmp_filename );
DMRGSCFrotations::rotate( VMAT_ORIG, NULL, theRotatedTEI, 'C', 'V', 'C', 'V', iHandler, unitary, mem1, mem2, work_mem_size, tmp_filename );
delete_file( tmp_filename );
}
delete [] mem1;
delete [] mem2;
double E_CASPT2 = 0.0;
if ( am_i_master ){
cout << "CASPT2 : Deviation from pseudocanonical = " << deviation_from_blockdiag( theFmatrix, iHandler ) << endl;
CheMPS2::CASPT2 * myCASPT2 = new CheMPS2::CASPT2( iHandler, theRotatedTEI, theTmatrix, theFmatrix, DMRG1DM, DMRG2DM, three_dm, contract, IPEA );
delete theRotatedTEI;
delete [] three_dm;
delete [] contract;
E_CASPT2 = myCASPT2->solve( IMAG );
delete myCASPT2;
} else {
delete theRotatedTEI;
delete [] three_dm;
delete [] contract;
}
#ifdef CHEMPS2_MPI_COMPILATION
MPIchemps2::broadcast_array_double( &E_CASPT2, 1, MPI_CHEMPS2_MASTER );
#endif
return E_CASPT2;
}
int main(void){
#ifdef CHEMPS2_MPI_COMPILATION
CheMPS2::MPIchemps2::mpi_init();
#endif
CheMPS2::Initialize::Init();
//The Hamiltonian: 1D Hubbard model
const int L = 10;
const int Group = 0;
const double U = 2.0;
const double T = -1.0;
int * irreps = new int[L];
for (int cnt=0; cnt<L; cnt++){ irreps[cnt] = 0; }
//The Hamiltonian initializes all its matrix elements to 0.0
CheMPS2::Hamiltonian * Ham = new CheMPS2::Hamiltonian(L, Group, irreps);
delete [] irreps;
for (int cnt=0; cnt<L; cnt++){ Ham->setVmat(cnt,cnt,cnt,cnt,U); }
for (int cnt=0; cnt<L-1; cnt++){ Ham->setTmat(cnt,cnt+1,T); }
//The targeted state
const int TwoS = 5;
const int N = 9;
const int Irrep = 0;
CheMPS2::Problem * Prob = new CheMPS2::Problem(Ham, TwoS, N, Irrep);
//The convergence scheme
CheMPS2::ConvergenceScheme * OptScheme = new CheMPS2::ConvergenceScheme(2);
//OptScheme->setInstruction(instruction, DSU(2), Econvergence, maxSweeps, noisePrefactor);
OptScheme->setInstruction(0, 30, 1e-10, 3, 0.1);
OptScheme->setInstruction(1, 1000, 1e-10, 10, 0.0);
//Run ground state calculation
CheMPS2::DMRG * theDMRG = new CheMPS2::DMRG(Prob, OptScheme);
const double EnergyDMRG = theDMRG->Solve();
theDMRG->calc2DMandCorrelations();
#ifdef CHEMPS2_MPI_COMPILATION
if ( CheMPS2::MPIchemps2::mpi_rank() == MPI_CHEMPS2_MASTER )
#endif
{
theDMRG->getCorrelations()->Print();
}
//Clean up DMRG
if (CheMPS2::DMRG_storeMpsOnDisk){ theDMRG->deleteStoredMPS(); }
if (CheMPS2::DMRG_storeRenormOptrOnDisk){ theDMRG->deleteStoredOperators(); }
delete theDMRG;
delete OptScheme;
delete Prob;
//Calculate FCI reference energy
double EnergyFCI = 0.0;
#ifdef CHEMPS2_MPI_COMPILATION
if ( CheMPS2::MPIchemps2::mpi_rank() == MPI_CHEMPS2_MASTER )
#endif
{
const int Nel_up = ( N + TwoS ) / 2;
const int Nel_down = ( N - TwoS ) / 2;
const double maxMemWorkMB = 10.0;
const int FCIverbose = 1;
CheMPS2::FCI * theFCI = new CheMPS2::FCI(Ham, Nel_up, Nel_down, Irrep, maxMemWorkMB, FCIverbose);
EnergyFCI = theFCI->GSDavidson(NULL);
delete theFCI;
}
#ifdef CHEMPS2_MPI_COMPILATION
CheMPS2::MPIchemps2::broadcast_array_double( &EnergyFCI, 1, MPI_CHEMPS2_MASTER );
#endif
//Clean up the Hamiltonian
delete Ham;
//Check succes
const bool success = ( fabs( EnergyDMRG - EnergyFCI ) < 1e-8 ) ? true : false;
#ifdef CHEMPS2_MPI_COMPILATION
CheMPS2::MPIchemps2::mpi_finalize();
#endif
cout << "================> Did test 4 succeed : ";
if (success){
cout << "yes" << endl;
return 0; //Success
}
cout << "no" << endl;
return 7; //Fail
}
