CI Namespace Reference

Functions and classes for Configuration Interaction calculations. More...

Classes
struct	ConfigInfo
	Basic configuration info for each CI level solution. More...
class	CSF2
	Very basic two-electron CSF. Only two-electron is implemented. More...
class	PsiJPi
	Stores the CI Solutions for given J and parity (only two-electron). More...

Functions
double	CSF2_Coulomb (const Coulomb::QkTable &qk, DiracSpinor::Index v, DiracSpinor::Index w, DiracSpinor::Index x, DiracSpinor::Index y, int twoJ)
	Calculates the anti-symmetrised Coulomb integral for 2-particle states: C1*C2*(g_abcd-g_abdc), where Cs are C.G. coefficients.
double	CSF2_Sigma2 (const Coulomb::LkTable &Sk, DiracSpinor::Index v, DiracSpinor::Index w, DiracSpinor::Index x, DiracSpinor::Index y, int twoJ)
	Calculates the correlation [Sigma(2)] correction to CSF2_Coulomb(). Sk is the table of two-body single-particle matrix elements of Sigma_2.
double	CSF2_Breit (const Coulomb::WkTable &Bk, DiracSpinor::Index v, DiracSpinor::Index w, DiracSpinor::Index x, DiracSpinor::Index y, int twoJ)
	Calculates the anti-symmetrised Breit integral for 2-particle states: C1*C2*(b_abcd-b_abdc), where Cs are C.G. coefficients.
double	Sigma2_AB (const CI::CSF2 &A, const CI::CSF2 &B, int twoJ, const Coulomb::LkTable &Sk)
	Calculates the Sigma(2) correction to Hab()
double	Breit_AB (const CI::CSF2 &A, const CI::CSF2 &B, int twoJ, const Coulomb::WkTable &Bk)
	Calculates the Breit correction to Hab()
double	Hab (const CI::CSF2 &A, const CI::CSF2 &B, int twoJ, const Coulomb::meTable< double > &h1, const Coulomb::QkTable &qk)
	Determines CI Hamiltonian matrix element for two 2-particle CSFs, a and b. Does NOT include Sigma(2) matrix, but does include Sigma1 (if it's in h1)
Coulomb::meTable< double >	calculate_h1_table (const std::vector< DiracSpinor > &ci_basis, const std::vector< DiracSpinor > &s1_basis_core, const std::vector< DiracSpinor > &s1_basis_excited, const Coulomb::QkTable &qk, bool include_Sigma1)
	Calculates table of single-particle matrix elements of one-body Hamiltonian. Note: assumes basis are Hartree-Fock eigenstates!
Coulomb::meTable< double >	calculate_h1_table (const std::vector< DiracSpinor > &ci_basis, const MBPT::CorrelationPotential &Sigma, bool include_Sigma1)
Coulomb::LkTable	calculate_Sk (const std::string &filename, const std::vector< DiracSpinor > &cis2_basis, const std::vector< DiracSpinor > &s2_basis_core, const std::vector< DiracSpinor > &s2_basis_excited, const Coulomb::QkTable &qk, int max_k, bool exclude_wrong_parity_box, bool no_new_integrals=false)
	Calculates table of single-particle matrix elements of two-body Sigma_2 operator.
Coulomb::WkTable	calculate_Bk (const std::string &bk_filename, const HF::Breit *const pBr, const std::vector< DiracSpinor > &ci_basis, int max_k, bool no_new_integralsQ=false)
	Calculates table of single-particle matrix elements of two-body Breit operator.
std::vector< DiracSpinor >	basis_subset (const std::vector< DiracSpinor > &basis, const std::string &subset_string, const std::string &frozen_core_string="")
	Takes a subset of input basis according to subset_string. Only states not included in frozen_core_string are included.
double	ReducedME (const LinAlg::View< const double > &cA, const std::vector< CI::CSF2 > &CSFAs, int twoJA, const LinAlg::View< const double > &cB, const std::vector< CI::CSF2 > &CSFBs, int twoJB, const Coulomb::meTable< double > &h, int K_rank, int Parity)
	Calculate reduced matrix elements between two CI states.
double	RME_CSF2 (const CI::CSF2 &X, int twoJX, const CI::CSF2 &V, int twoJV, const Coulomb::meTable< double > &h, int K_rank)
	Calculate reduce ME between two 2-particle CSFs - XXX not quite right??
std::pair< int, int >	Term_S_L (int l1, int l2, int twoJ, double gJ_target)
	Determines best-fit for S and L for two-electron state by matching g-factor.
std::string	Term_Symbol (int two_J, int L, int two_S, int parity)
	Returns Term_Symbol as string.
std::string	Term_Symbol (int L, int two_S, int parity)
	Returns Term_Symbol as string, without J part.
LinAlg::Matrix< double >	construct_Hci (const PsiJPi &psi, const Coulomb::meTable< double > &h1, const Coulomb::QkTable &qk, const Coulomb::WkTable *Bk=nullptr, const Coulomb::LkTable *Sk=nullptr)
	Constructs the CI matrix, optionally including Sigma corrections.
double	ReducedME (const PsiJPi &As, std::size_t iA, const PsiJPi &Bs, std::size_t iB, const Coulomb::meTable< double > &h, int K_rank, int Parity)
	Calculate reduced matrix elements between two CI states.
std::vector< PsiJPi >	configuration_interaction (const IO::InputBlock &input, const Wavefunction &wf)
	Runs configuration interaction with options specified by input. Returns a list of PsiJPi (set of CI solutions for list of J/Pi)
PsiJPi	run_CI (const std::vector< DiracSpinor > &ci_sp_basis, int twoJ, int parity, int num_solutions, std::optional< double > all_below, const Coulomb::meTable< double > &h1, const Coulomb::QkTable &qk, const Coulomb::WkTable &Bk, const Coulomb::LkTable &Sk, bool include_Sigma2, std::ostream &outstream=std::cout)
	Performs CI for specified J and Pi.
bool	operator== (const CSF2 &A, const CSF2 &B)
bool	operator!= (const CSF2 &A, const CSF2 &B)
std::vector< CSF2 >	form_CSFs (int twoJ, int parity, const std::vector< DiracSpinor > &cisp_basis)
	Forms list of all possible (2-particle) CSFs with given J and parity.

Detailed Description

Functions and classes for Configuration Interaction calculations.

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Class Documentation

CI::ConfigInfo

struct CI::ConfigInfo

Basic configuration info for each CI level solution.

Class Members
string	config {}
double	ci2 {0.0}
double	gJ {0.0}
double	L {-1.0}
double	twoS {-1.0}

Function Documentation

CSF2_Coulomb()

double CI::CSF2_Coulomb	(	const Coulomb::QkTable &	qk,
		DiracSpinor::Index	v,
		DiracSpinor::Index	w,
		DiracSpinor::Index	x,
		DiracSpinor::Index	y,
		int	twoJ
	)

Calculates the anti-symmetrised Coulomb integral for 2-particle states: C1*C2*(g_abcd-g_abdc), where Cs are C.G. coefficients.

CSF2_Sigma2()

double CI::CSF2_Sigma2	(	const Coulomb::LkTable &	Sk,
		DiracSpinor::Index	v,
		DiracSpinor::Index	w,
		DiracSpinor::Index	x,
		DiracSpinor::Index	y,
		int	twoJ
	)

Calculates the correlation [Sigma(2)] correction to CSF2_Coulomb(). Sk is the table of two-body single-particle matrix elements of Sigma_2.

CSF2_Breit()

double CI::CSF2_Breit	(	const Coulomb::WkTable &	Bk,
		DiracSpinor::Index	v,
		DiracSpinor::Index	w,
		DiracSpinor::Index	x,
		DiracSpinor::Index	y,
		int	twoJ
	)

Calculates the anti-symmetrised Breit integral for 2-particle states: C1*C2*(b_abcd-b_abdc), where Cs are C.G. coefficients.

Sigma2_AB()

double CI::Sigma2_AB	(	const CI::CSF2 &	A,
		const CI::CSF2 &	B,
		int	twoJ,
		const Coulomb::LkTable &	Sk
	)

Calculates the Sigma(2) correction to Hab()

Breit_AB()

double CI::Breit_AB	(	const CI::CSF2 &	A,
		const CI::CSF2 &	B,
		int	twoJ,
		const Coulomb::WkTable &	Bk
	)

Calculates the Breit correction to Hab()

Hab()

double CI::Hab	(	const CI::CSF2 &	X,
		const CI::CSF2 &	V,
		int	twoJ,
		const Coulomb::meTable< double > &	h1,
		const Coulomb::QkTable &	qk
	)

Determines CI Hamiltonian matrix element for two 2-particle CSFs, a and b. Does NOT include Sigma(2) matrix, but does include Sigma1 (if it's in h1)

calculate_h1_table()

Coulomb::meTable< double > CI::calculate_h1_table	(	const std::vector< DiracSpinor > &	ci_basis,
		const std::vector< DiracSpinor > &	s1_basis_core,
		const std::vector< DiracSpinor > &	s1_basis_excited,
		const Coulomb::QkTable &	qk,
		bool	include_Sigma1
	)

Calculates table of single-particle matrix elements of one-body Hamiltonian. Note: assumes basis are Hartree-Fock eigenstates!

calculate_Sk()

Coulomb::LkTable CI::calculate_Sk	(	const std::string &	filename,
		const std::vector< DiracSpinor > &	cis2_basis,
		const std::vector< DiracSpinor > &	s2_basis_core,
		const std::vector< DiracSpinor > &	s2_basis_excited,
		const Coulomb::QkTable &	qk,
		int	max_k,
		bool	exclude_wrong_parity_box,
		bool	no_new_integrals
	)

Calculates table of single-particle matrix elements of two-body Sigma_2 operator.

calculate_Bk()

Coulomb::WkTable CI::calculate_Bk	(	const std::string &	bk_filename,
		const HF::Breit *const	pBr,
		const std::vector< DiracSpinor > &	ci_basis,
		int	max_k,
		bool	no_new_integrals
	)

Calculates table of single-particle matrix elements of two-body Breit operator.

basis_subset()

std::vector< DiracSpinor > CI::basis_subset	(	const std::vector< DiracSpinor > &	basis,
		const std::string &	subset_string,
		const std::string &	frozen_core_string
	)

Takes a subset of input basis according to subset_string. Only states not included in frozen_core_string are included.

ReducedME() [1/2]

double CI::ReducedME	(	const LinAlg::View< const double > &	cA,
		const std::vector< CI::CSF2 > &	CSFAs,
		int	twoJA,
		const LinAlg::View< const double > &	cB,
		const std::vector< CI::CSF2 > &	CSFBs,
		int	twoJB,
		const Coulomb::meTable< double > &	h,
		int	K_rank,
		int	Parity
	)

Calculate reduced matrix elements between two CI states.

cA is CI expansion coefficients (row if CI eigenvector matrix). h is lookup table of single-particle matrix elements of operator.

RME_CSF2()

double CI::RME_CSF2	(	const CI::CSF2 &	X,
		int	twoJX,
		const CI::CSF2 &	V,
		int	twoJV,
		const Coulomb::meTable< double > &	h,
		int	K_rank
	)

Calculate reduce ME between two 2-particle CSFs - XXX not quite right??

Term_S_L()

std::pair< int, int > CI::Term_S_L	(	int	l1,
		int	l2,
		int	twoJ,
		double	gJ_target
	)

Determines best-fit for S and L for two-electron state by matching g-factor.

Term_Symbol() [1/2]

std::string CI::Term_Symbol	(	int	two_J,
		int	L,
		int	two_S,
		int	parity
	)

Returns Term_Symbol as string.

Term_Symbol() [2/2]

std::string CI::Term_Symbol	(	int	L,
		int	two_S,
		int	parity
	)

Returns Term_Symbol as string, without J part.

construct_Hci()

LinAlg::Matrix< double > CI::construct_Hci	(	const PsiJPi &	psi,
		const Coulomb::meTable< double > &	h1,
		const Coulomb::QkTable &	qk,
		const Coulomb::WkTable *	Bk = nullptr,
		const Coulomb::LkTable *	Sk = nullptr
	)

Constructs the CI matrix, optionally including Sigma corrections.

h1 is table of one-body <a|h1|b> matrix elements, and may include Sigma_1. qk contains two-body Coulomb integrals <vw|q^k|xy>. Sk is optional; if given, constains two-body <vw|Sigma_2|xy> corrections.

ReducedME() [2/2]

double CI::ReducedME ( const PsiJPi &  As, std::size_t  iA, const PsiJPi &  Bs, std::size_t  iB, const Coulomb::meTable< double > &  h, int  K_rank, int  Parity  )

inline

Calculate reduced matrix elements between two CI states.

As is a PsiJPi (set of CI solutions for given J and pi), iA is which solution to calculate for. h is lookup table of single-particle matrix elements of operator.

configuration_interaction()

std::vector< PsiJPi > CI::configuration_interaction	(	const IO::InputBlock &	input,
		const Wavefunction &	wf
	)

Runs configuration interaction with options specified by input. Returns a list of PsiJPi (set of CI solutions for list of J/Pi)

run_CI()

PsiJPi CI::run_CI	(	const std::vector< DiracSpinor > &	ci_sp_basis,
		int	twoJ,
		int	parity,
		int	num_solutions,
		std::optional< double >	all_below,
		const Coulomb::meTable< double > &	h1,
		const Coulomb::QkTable &	qk,
		const Coulomb::WkTable &	Bk,
		const Coulomb::LkTable &	Sk,
		bool	include_Sigma2,
		std::ostream &	outstream
	)

Performs CI for specified J and Pi.

form_CSFs()

std::vector< CSF2 > CI::form_CSFs	(	int	twoJ,
		int	parity,
		const std::vector< DiracSpinor > &	cisp_basis
	)

Forms list of all possible (2-particle) CSFs with given J and parity.