#include <FourIndex.h>

Public Member Functions
	FourIndex (const int nGroup, const int *IrrepSizes)
	Constructor. More...

virtual	~FourIndex ()
	Destructor.

void	Clear ()
	Set all two-body matrix elements to zero.

void	set (const int irrep_i, const int irrep_j, const int irrep_k, const int irrep_l, const int i, const int j, const int k, const int l, const double val)
	Set an element. More...

void	add (const int irrep_i, const int irrep_j, const int irrep_k, const int irrep_l, const int i, const int j, const int k, const int l, const double val)
	Add a double to an element. More...

double	get (const int irrep_i, const int irrep_j, const int irrep_k, const int irrep_l, const int i, const int j, const int k, const int l) const
	Get an element. More...

int	get_irrep_size (const int irrep) const
	Get a given irrep size. More...

void	save (const std::string name) const
	Save the FourIndex object. More...

void	read (const std::string name)
	Load the FourIndex object. More...

Detailed Description

FourIndex class.

Author: Sebastian Wouters sebas.nosp@m.tian.nosp@m.woute.nosp@m.rs@g.nosp@m.mail..nosp@m.com

Date: February 8, 2013

Container class for four-index tensors with Abelian point group symmetry (real character table; see Irreps.h): 2-particle matrix elements. The four-index tensor element V_ijkl has 8-fold permutation symmetry and is only nonzero when I_i x I_j = I_k x I_l. To clarify the convention, the potential energy is given:
$\frac{1}{2} \sum\limits_{ijkl\sigma\tau} V_{ijkl} \delta_{I_i \otimes I_j \otimes I_k \otimes I_l, I_{trivial}} \hat{a}_{i \sigma}^{\dagger} \hat{a}_{j \tau}^{\dagger} \hat{a}_{l \tau} \hat{a}_{k \sigma}$ .
Hence $V_{ijkl} = ( ij \mid V \mid kl )$ in physics notation, i.e. with i and k the same integration coordinate for the electron repulsion integrals.

Definition at line 34 of file FourIndex.h.

Constructor & Destructor Documentation

CheMPS2::FourIndex::FourIndex	(	const int	nGroup,
		const int *	IrrepSizes
	)

Constructor.

Parameters

nGroup	The symmetry group number (see Irreps.h)
IrrepSizes	Array with length the number of irreps of the specified group, containing the number of orbitals of that irrep

Definition at line 34 of file FourIndex.cpp.

Member Function Documentation

void CheMPS2::FourIndex::add	(	const int	irrep_i,
		const int	irrep_j,
		const int	irrep_k,
		const int	irrep_l,
		const int	i,
		const int	j,
		const int	k,
		const int	l,
		const double	val
	)

Add a double to an element.

Parameters

irrep_i	The irrep number of the first orbital (see Irreps.h)
irrep_j	The irrep number of the second orbital
irrep_k	The irrep number of the third orbital
irrep_l	The irrep number of the fourth orbital
i	The first index (within the symmetry block)
j	The second index (within the symmetry block)
k	The third index (within the symmetry block)
l	The fourth index (within the symmetry block)
val	The value which should be added to the matrixelement

Definition at line 169 of file FourIndex.cpp.

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double CheMPS2::FourIndex::get	(	const int	irrep_i,
		const int	irrep_j,
		const int	irrep_k,
		const int	irrep_l,
		const int	i,
		const int	j,
		const int	k,
		const int	l
	)		const

Get an element.

Parameters

irrep_i	The irrep number of the first orbital (see Irreps.h)
irrep_j	The irrep number of the second orbital
irrep_k	The irrep number of the third orbital
irrep_l	The irrep number of the fourth orbital
i	The first index (within the symmetry block)
j	The second index (within the symmetry block)
k	The third index (within the symmetry block)
l	The fourth index (within the symmetry block)

Definition at line 175 of file FourIndex.cpp.

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int CheMPS2::FourIndex::get_irrep_size ( const int irrep ) const

Get a given irrep size.

Parameters

irrep The irrep for which you want to know the irrep size

Returns: The corresponding irrep size

Definition at line 294 of file FourIndex.cpp.

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void CheMPS2::FourIndex::read ( const std::string name )

Load the FourIndex object.

Parameters

name filename

Definition at line 372 of file FourIndex.cpp.

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void CheMPS2::FourIndex::save ( const std::string name ) const

Save the FourIndex object.

Parameters

name filename

Definition at line 314 of file FourIndex.cpp.

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void CheMPS2::FourIndex::set	(	const int	irrep_i,
		const int	irrep_j,
		const int	irrep_k,
		const int	irrep_l,
		const int	i,
		const int	j,
		const int	k,
		const int	l,
		const double	val
	)

Set an element.

Parameters

irrep_i	The irrep number of the first orbital (see Irreps.h)
irrep_j	The irrep number of the second orbital
irrep_k	The irrep number of the third orbital
irrep_l	The irrep number of the fourth orbital
i	The first index (within the symmetry block)
j	The second index (within the symmetry block)
k	The third index (within the symmetry block)
l	The fourth index (within the symmetry block)
val	The value to which the element of the matrix should be set

Definition at line 163 of file FourIndex.cpp.

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

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation