# sc::SCF Class Reference

The SCF class is the base for all classes that use a self-consistent field procedure to solve an effective one body problem. More...

`#include <scf.h>`

Inheritance diagram for sc::SCF:

List of all members.

## Public Member Functions

| SCF (StateIn &)
| SCF (const Ref< KeyVal > &)
| The KeyVal constructor.
void | save_data_state (StateOut &)
| Save the base classes (with save_data_state) and the members in the same order that the StateIn CTOR initializes them.
RefSCMatrix | oso_eigenvectors ()
| Returns the orthogonal MO (columns) to orthogonal-SO (rows) transformation matrix.
RefDiagSCMatrix | eigenvalues ()
| Returns the MO basis eigenvalues.
int | spin_unrestricted ()
| Return 1 if the alpha orbitals are not equal to the beta orbitals.
virtual int | n_fock_matrices () const=0
virtual RefSymmSCMatrix | fock (int)=0
virtual RefSymmSCMatrix | effective_fock ()=0
virtual double | one_body_energy ()
virtual void | two_body_energy (double &ec, double &ex)
void | symmetry_changed ()
| Call this if you have changed the molecular symmetry of the molecule contained by this MolecularEnergy.
void | obsolete ()
| Marks all results as being out of date.
void | print (std::ostream &o=ExEnv::out0()) const
| Print information about the object.

## Protected Types

enum | Access { Read, Write, Accum }

## Protected Member Functions

virtual void | init_threads ()
virtual void | done_threads ()
virtual void | compute ()
| Recompute at least the results that have compute true and are not already computed.
virtual double | compute_vector (double &, double enuclear)
virtual Ref< SCExtrapError > | extrap_error ()
virtual void | compute_gradient (const RefSCVector &)
virtual void | compute_hessian (const RefSymmSCMatrix &)
virtual void | savestate_iter (int)
virtual void | savestate_to_file (const std::string &filename)
signed char * | init_pmax (double *)
RefSymmSCMatrix | get_local_data (const RefSymmSCMatrix &, double *&, Access)
virtual void | initial_vector (int needv=1)
void | init_mem (int)
void | so_density (const RefSymmSCMatrix &d, double occ, int alp=1)
int * | read_occ (const Ref< KeyVal > &, const char *name, int nirrep)
virtual void | set_occupations (const RefDiagSCMatrix &)=0
virtual void | init_vector ()=0
virtual void | done_vector ()=0
virtual double | new_density ()=0
virtual void | reset_density ()=0
virtual double | scf_energy ()=0
virtual Ref< SCExtrapData > | extrap_data ()=0
virtual void | ao_fock (double accuracy)=0
virtual void | init_gradient ()=0
virtual void | done_gradient ()=0
virtual RefSymmSCMatrix | lagrangian ()=0
virtual RefSymmSCMatrix | gradient_density ()=0
virtual void | two_body_deriv (double *)=0
virtual void | init_hessian ()=0
virtual void | done_hessian ()=0

## Protected Attributes

int | need_vec_
int | compute_guess_
int | keep_guess_wfn_
Ref< OneBodyWavefunction > | guess_wfn_
int | always_use_guess_wfn_
Ref< SelfConsistentExtrapolation > | extrap_
Ref< AccumH > | accumdih_
Ref< AccumH > | accumddh_
int | maxiter_
int | dens_reset_freq_
int | reset_occ_
int | local_dens_
size_t | storage_
int | print_all_evals_
int | print_occ_evals_
double | level_shift_
Ref< MessageGrp > | scf_grp_
Ref< ThreadGrp > | threadgrp_
int | local_
Ref< TwoBodyInt > * | tbis_
std::string | previous_savestate_file_
RefSCMatrix | oso_scf_vector_
RefSCMatrix | oso_scf_vector_beta_
RefSymmSCMatrix | hcore_

## Detailed Description

The SCF class is the base for all classes that use a self-consistent field procedure to solve an effective one body problem.

## Constructor & Destructor Documentation

sc::SCF::SCF | ( | const Ref< KeyVal > & |  | ) |

The KeyVal constructor.

`maxiter`
  This integer specifies the maximum number of SCF iterations. The default is 40.

`density_reset_frequency`
  This integer specifies how often, in term of SCF iterations, will be reset to . The default is 10.

`reset_occuptions`
  Reassign the occupations after each iteration based on the eigenvalues. This only has an effect for molecules with higher than symmetry. The default is false.

`level_shift`
  The default is 0.

`extrap`
  This specifies an object of type SelfConsistentExtrapolation. The default is a DIIS object.

`memory`
  The amount of memory that each processor may use. The default is 0 (minimal memory use).

`local_density`
  If this is true, a local copy of the density and matrix will be made on all nodes, even if a distributed matrix specialization is used. The default is true.

`guess_wavefunction`
  This specifies the initial guess for the solution to the SCF equations. This can be either a OneBodyWavefunction object or the name of file that contains the saved state of a OneBodyWavefunction object. By default the one-electron hamiltonian will be diagonalized to obtain the initial guess.

`keep_guess_wavefunction`
  The guess wavefunction is normally discarded after it is projected. Setting this boolean variable to true will cause the guess to be kept. This is useful when doing frequencies of symmetric molecules by finite displacements, because the wavefunction is lost whenever the molecule is displaced into lower symmetry.

`always_use_guess_wavefunction`
  If the orbitals must be recomputed after they have already been computed once, then the old orbitals are used as the initial guess by default. However, if this option is true, then the guess wavefunction will be used, if available. If a guess wavefunction is not available, then a core Hamiltonian guess will be used. If this option is set to true, then keep_guess_wavefunction should also be set to true.

`print_evals`
  Takes a boolean value. If true, print all eigenvalues after the SCF procedure converges. Takes a boolean value. The default is false.

`print_occ_evals`
  Takes a boolean value. If true, print the occupied eigenvalues after the SCF procedure converges. The default is false.

## Member Function Documentation

virtual void sc::SCF::compute | ( |  | ) | `[protected, virtual]`

Recompute at least the results that have compute true and are not already computed.

This should only be called by Result's members.

Implements sc::Compute.

void sc::SCF::save_data_state | ( | StateOut & |  | ) | `[virtual]`

Save the base classes (with save_data_state) and the members in the same order that the StateIn CTOR initializes them.

This must be implemented by the derived class if the class has data.

Reimplemented from sc::OneBodyWavefunction.

Reimplemented in sc::CLKS, sc::HSOSKS, sc::UKS, sc::CLHF, sc::CLSCF, sc::HSOSHF, sc::HSOSSCF, sc::UHF, and sc::UnrestrictedSCF.

RefSCMatrix sc::SCF::oso_eigenvectors | ( |  | ) | `[virtual]`

Returns the orthogonal MO (columns) to orthogonal-SO (rows) transformation matrix.

Implements sc::OneBodyWavefunction.

RefDiagSCMatrix sc::SCF::eigenvalues | ( |  | ) | `[virtual]`

Returns the MO basis eigenvalues.

Implements sc::OneBodyWavefunction.

Reimplemented in sc::UnrestrictedSCF.

void sc::SCF::symmetry_changed | ( |  | ) | `[virtual]`

Call this if you have changed the molecular symmetry of the molecule contained by this MolecularEnergy.

Reimplemented from sc::OneBodyWavefunction.

Reimplemented in sc::CLSCF, sc::HSOSSCF, and sc::UnrestrictedSCF.

void sc::SCF::obsolete | ( |  | ) | `[virtual]`

Marks all results as being out of date.

Any subsequent access to results will cause Compute::compute() to be called.

Reimplemented from sc::Wavefunction.

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

- scf.h