Base class for describing objects containing the band structure, i.e. More...

#include <bandstructure.h>

Inheritance diagram for BaseBandStructure:

Public Member Functions
virtual	~BaseBandStructure ()=default
	Base destructor for bandstructure class, silences warnings.

virtual Particle	getParticle ()=0
	Get the Particle object associated with this class. More...

virtual Points	getPoints ()=0
	Returns the wavevectors on which the band structure is computed. More...

virtual Point	getPoint (const int &pointIndex)=0
	Returns a wavevector, given a wavevector index. More...

virtual int	getNumPoints (const bool &useFullGrid=false)=0
	Returns the total number of k/q-points. More...

virtual int	getNumBands ()=0
	Returns the number of bands. More...

virtual int	getFullNumBands ()=0

virtual int	getNumBands (WavevectorIndex &ik)=0
	Returns the number of bands. More...

virtual int	hasWindow ()=0
	Checks whether the bandStructure has been built discarding some Bloch states from those available. More...

virtual bool	getIsDistributed ()=0
	Returns the boolean determining if this band structure is distributed or not.

virtual size_t	getIndex (const WavevectorIndex &ik, const BandIndex &ib)=0
	Builds a Bloch state index, which combines both wavevector index and band index. More...

virtual std::tuple< WavevectorIndex, BandIndex >	getIndex (const int &is)=0
	Given a Bloch state index, finds the corresponding wavevector and band index. More...

virtual std::tuple< WavevectorIndex, BandIndex >	getIndex (StateIndex &is)=0

virtual int	getNumStates ()=0
	Returns the total number of Bloch states. More...

virtual std::vector< size_t >	parallelStateIterator ()
	Returns an iterator to be used for loops over the Bloch state index. More...

virtual const double &	getEnergy (StateIndex &is)=0
	Returns the energy of a quasiparticle from its Bloch index Used for accessing the band structure in the BTE. More...

virtual Eigen::VectorXd	getEnergies (WavevectorIndex &ik)=0

virtual double	getMaxEnergy ()=0
	Return the maximum energy of a bandstructure. More...

virtual Eigen::Vector3d	getGroupVelocity (StateIndex &is)=0
	Returns the velocity of a quasiparticle from its Bloch index Used for accessing the band structure in the BTE. More...

virtual Eigen::MatrixXd	getGroupVelocities (WavevectorIndex &ik)=0

virtual Eigen::Tensor< std::complex< double >, 3 >	getVelocities (WavevectorIndex &ik)=0

virtual Eigen::MatrixXcd	getEigenvectors (WavevectorIndex &ik)=0

virtual Eigen::Tensor< std::complex< double >, 3 >	getPhEigenvectors (WavevectorIndex &ik)=0

virtual Eigen::Vector3d	getWavevector (StateIndex &is)=0
	Returns the wavevector of a quasiparticle from its Bloch index Used for accessing the band structure in the BTE. More...

virtual Eigen::Vector3d	getWavevector (WavevectorIndex &ik)=0

virtual void	setEnergies (Point &point, Eigen::VectorXd &energies_)=0
	Method to save quasiparticle eigenvectors inside FullBandStructure(). More...

virtual void	setEigenvectors (Point &point, Eigen::MatrixXcd &eigenvectors_)=0
	Method to save quasiparticle eigenvectors inside FullBandStructure(). More...

virtual void	setVelocities (Point &point, Eigen::Tensor< std::complex< double >, 3 > &velocities_)=0
	Saves in the class the velocities computed at a particular point. More...

virtual std::vector< Eigen::Matrix3d >	getRotationsStar (WavevectorIndex &ikIndex)=0
	Given a irreducible point index, find the list of rotations to reconstruct the equivalent points. More...

virtual std::vector< Eigen::Matrix3d >	getRotationsStar (StateIndex &isIndex)=0
	Given an irreducible Bloch state (i.e. More...

virtual std::tuple< int, Eigen::Matrix3d >	getRotationToIrreducible (const Eigen::Vector3d &x, const int &basis=Points::crystalCoordinates)=0
	Given a point in crystal or cartesian coordinates, returns the index of the irreducible point and the rotation such that rotation*irrPoint = redPoint. More...

virtual BteIndex	stateToBte (StateIndex &isIndex)=0
	Utility method to convert an index over Bloch states in the band structure into a Bloch state index usable by VectorBTE. More...

virtual StateIndex	bteToState (BteIndex &iBteIndex)=0
	Utility method to convert an index over Bloch states in a VectorBTE into the Bloch state index in the band structure. More...

virtual std::vector< int >	irrStateIterator ()=0
	Iterator over the Bloch states in the band structure, over just the irreducible wavevectors, but isn't distributed over MPI processes. More...

virtual std::vector< int >	parallelIrrStateIterator ()=0
	Iterator over the Bloch states in the band structure, distributed over MPI processes, running only over irreducible wavevectors. More...

virtual std::vector< int >	irrPointsIterator ()=0
	Iterator over the irreducible points indices. More...

virtual std::vector< int >	parallelIrrPointsIterator ()=0
	Iterator over the irreducible points indices. More...

virtual int	getNumIrrStates ()=0
	Returns number of irr points for this band structure.

virtual int	getPointIndex (const Eigen::Vector3d &crystalCoordinates, const bool &suppressError=false)=0
	Find the index of a point in the reducible list of points, given its coordinates in the crystal basis. More...

virtual std::vector< int >	getReducibleStarFromIrreducible (const int &ik)=0
	Method to find the points equivalent to an irreducible point. More...

void	outputComponentsToJSON (const std::string &outFileName="bandstructure.json")
	Outputs the bandstructure information to file, either sym reduced or not. More...

void	printBandStructureStateInfo (const int &fullNumBands)
	A function to print information about how many states are in this bandstructure, and how things were reduced by filtering of states. More...

Detailed Description

the harmonic properties of a quasiparticle, as a function of wavevectors (Points).

Member Function Documentation

◆ bteToState()

virtual StateIndex BaseBandStructure::bteToState ( BteIndex & iBteIndex )

pure virtual

Unlike stateToBte, this should always have a solution.

Parameters

iBteIndex index of the Bloch state in the BTE

Returns: StateIndex: the index of the Bloch state in the band structure.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getEnergy()

virtual const double& BaseBandStructure::getEnergy ( StateIndex & is )

pure virtual

Parameters

stateIndex an integer index in range [0,numStates[

Returns: energy: the value of the QP energy for that given Bloch index. Phonon energies are referred to zero, with negative energies being actually complex phonon frequencies. Electronic energies are not saved with any particular reference, and should be used together with the chemical potential computed by StatisticsSweep. By policy, it's in rydberg units.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getGroupVelocity()

virtual Eigen::Vector3d BaseBandStructure::getGroupVelocity ( StateIndex & is )

pure virtual

Parameters

stateIndex an integer index in range [0,numStates[

Returns: velocity: a 3d vector with velocity. By policy, we save it in the cartesian basis and in atomic rydberg units.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getIndex() [1/2]

virtual std::tuple<WavevectorIndex, BandIndex> BaseBandStructure::getIndex ( const int & is )

pure virtual

Parameters

stateIndex StateIndex integer from 0 to numStates - 1 = numBands*numPoints-1

Returns: WavevectorIndex: strong-typed index on wavevector; BandIndex: strong-typed index on bands

Implemented in FullBandStructure, and ActiveBandStructure.

◆ getIndex() [2/2]

virtual size_t BaseBandStructure::getIndex	(	const WavevectorIndex &	ik,
		const BandIndex &	ib
	)

pure virtual

It's used to view the various matrices such as energy as a 1D vector, and can be used in combination with get() methods.

Parameters

wavevectorIndex strong-typed index on wavevector

Returns: stateIndex: integer from 0 to numStates-1=numBands*numPoints-1

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getMaxEnergy()

virtual double BaseBandStructure::getMaxEnergy ( )

pure virtual

Used when ph energy maximum is a cutoff for phel scattering.

Returns: maxEnergy: maximum energy value of bandstructure in Ry

Implemented in FullBandStructure, and ActiveBandStructure.

◆ getNumBands() [1/2]

virtual int BaseBandStructure::getNumBands ( )

pure virtual

Returns: numBands: the total number of bands present in the bandstructure. If the number of bands is not constant, calls an error.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getNumBands() [2/2]

virtual int BaseBandStructure::getNumBands ( WavevectorIndex & ik )

pure virtual

If the band structure is active, and there are a different number of bands at each wavevector, this function returns the number of bands at that point. If not, this defaults to the behavior of getNumBands() and just returns the number of bands. This is necessary for parts of the code where we leave an option to swap in different child band structure types.

Implemented in FullBandStructure, and ActiveBandStructure.

◆ getNumPoints()

virtual int BaseBandStructure::getNumPoints ( const bool & useFullGrid = false )

pure virtual

Parameters

useFullGrid default = false. If true, returns the number of points of the full monkhorst-pack grid of wavevectors, otherwise, returns the number of wavevectors stored in the BandStructure.

Returns: numPoints: the total number of wavevectors of the bandStructure.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getNumStates()

virtual int BaseBandStructure::getNumStates ( )

pure virtual

Returns: numStates: the integer number of Bloch states.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getParticle()

virtual Particle BaseBandStructure::getParticle ( )

pure virtual

Returns: particle: a Particle object, describing e.g. whether this is a phonon or electron bandStructure

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getPoint()

virtual Point BaseBandStructure::getPoint ( const int & pointIndex )

pure virtual

The wavevector index runs from 0 to numPoints-1

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getPointIndex()

virtual int BaseBandStructure::getPointIndex	(	const Eigen::Vector3d &	crystalCoordinates,
		const bool &	suppressError = `false`
	)

pure virtual

Parameters

crystalCoordinates	coordinates of the point in crystal basis
suppressError	default false. If false, will throw an error if the point is not found

Returns: ik: the index of the point

Implemented in FullBandStructure, and ActiveBandStructure.

◆ getPoints()

virtual Points BaseBandStructure::getPoints ( )

pure virtual

Returns: Points: the object representing the Brillouin zone wavevectors.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getReducibleStarFromIrreducible()

virtual std::vector<int> BaseBandStructure::getReducibleStarFromIrreducible ( const int & ik )

pure virtual

Parameters

ik	index of the irreducible point, with ik running on the full list of reducible points.

Returns: vector<int>: the list of indices of the reducible points equivalent to point #ik.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getRotationsStar() [1/2]

virtual std::vector<Eigen::Matrix3d> BaseBandStructure::getRotationsStar ( StateIndex & isIndex )

pure virtual

any band at an irreducible point), find the list of rotations to reconstruct the equivalent points.

Parameters

isIndex Index of the irreducible Bloch State. This index is a number between 0 and numStates.

Returns: rotations: a vector with the rotations used to reconstruct the symmetry-equivalent Bloch states.

Implemented in FullBandStructure, and ActiveBandStructure.

◆ getRotationsStar() [2/2]

virtual std::vector<Eigen::Matrix3d> BaseBandStructure::getRotationsStar ( WavevectorIndex & ikIndex )

pure virtual

Parameters

ikIndex Index of the irreducible wavevector. This index is a number between 0 and N_k_reducible.

Returns: rotations: a vector with the rotations used to reconstruct the symmetry-equivalent Bloch states.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getRotationToIrreducible()

virtual std::tuple<int, Eigen::Matrix3d> BaseBandStructure::getRotationToIrreducible	(	const Eigen::Vector3d &	x,
		const int &	basis = `Points::crystalCoordinates`
	)

pure virtual

Parameters

x	point coordinates
basis	either Points::crystalCoordinates or Points::cartesianCoordinates, this will treat x in the appropriate coordinate. Also the returned rotation will be in the corresponding basis.

Returns: <ik,rot>: a tuple with the index of the irreducible point and the rotation matrix connecting the irreducible and reducible point.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ getWavevector()

virtual Eigen::Vector3d BaseBandStructure::getWavevector ( StateIndex & is )

pure virtual

Parameters

stateIndex an integer index in range [0,numStates[

Returns: wavevector: a 3d vector with the wavevector in cartesian coordinates in units of Bohr^-1.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ hasWindow()

virtual int BaseBandStructure::hasWindow ( )

pure virtual

Returns: windowMethod: one of the values of Window::filterMethod. 0 for no filter.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ irrPointsIterator()

virtual std::vector<int> BaseBandStructure::irrPointsIterator ( )

pure virtual

The iterator is serial, not parallelized with MPI.

Returns: k-indices: a std::vector<int> with the indices of the irreducible points.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ irrStateIterator()

virtual std::vector<int> BaseBandStructure::irrStateIterator ( )

pure virtual

Returns: State-indices: a vector<int> with the indices over Bloch states stored in the band structure

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ outputComponentsToJSON()

void BaseBandStructure::outputComponentsToJSON ( const std::string & outFileName = "bandstructure.json" )

Parameters

outFileName	: optional output file name
symReduced	: if the bandstructure info should be sym reduced or not

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◆ parallelIrrPointsIterator()

virtual std::vector<int> BaseBandStructure::parallelIrrPointsIterator ( )

pure virtual

The iterator is parallelized over MPI processes.

Returns: k-indices: a std::vector<int> with the indices of the irreducible points.

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ parallelIrrStateIterator()

virtual std::vector<int> BaseBandStructure::parallelIrrStateIterator ( )

pure virtual

Returns: State-indices: a vector<int> with the indices over Bloch states stored in the band structure

Implemented in FullBandStructure, and ActiveBandStructure.

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◆ parallelStateIterator()

std::vector< size_t > BaseBandStructure::parallelStateIterator ( )

virtual

The values of the iterator are distributed in N blocks over N MPI ranks.

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◆ printBandStructureStateInfo()

void BaseBandStructure::printBandStructureStateInfo ( const int & fullNumBands )

Parameters

fullNumBands The maximum number of bands possible

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◆ setEigenvectors()

virtual void BaseBandStructure::setEigenvectors	(	Point &	point,
		Eigen::MatrixXcd &	eigenvectors_
	)

pure virtual

Note that in this case, eigenvectors are passed as a matrix, which is the case e.g. for the Wannier interpolation, where the eigenvectors represent the unitary transformation matrix U for Wannier localization.

Parameters

point	a Point object with the coordinates of the wavevector, which should come from the same Point class stored in FullBandStructure
eigenvectors	a complex matrix of size (numBands,numBands)

Implemented in FullBandStructure, and ActiveBandStructure.

◆ setEnergies()

virtual void BaseBandStructure::setEnergies	(	Point &	point,
		Eigen::VectorXd &	energies_
	)

pure virtual

Parameters

point	a vector of 3 crystal coordinates. The method will look for the wavevector index.
energies	a vector of size (numBands) with the quasiparticle energies

Implemented in FullBandStructure, and ActiveBandStructure.

◆ setVelocities()

virtual void BaseBandStructure::setVelocities	(	Point &	point,
		Eigen::Tensor< std::complex< double >, 3 > &	velocities_
	)

pure virtual

Parameters

point	a Point object representing the wavevector where these velocities have been computed.
velocities	a rank-3 tensor of size (numBands,numBands,3) containing the matrix elements of the velocity operator. Diagonal elements are the quasiparticle group velocities.

Implemented in FullBandStructure, and ActiveBandStructure.

◆ stateToBte()

virtual BteIndex BaseBandStructure::stateToBte ( StateIndex & isIndex )

pure virtual

If a state is not mapped to the VectorBTE, throws an error.

Parameters

StateIndex the index of the Bloch state in the band structure.

Returns: BteIndex: index of the Bloch state in the BTE

Implemented in FullBandStructure, and ActiveBandStructure.

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Public Member Functions

Detailed Description

Member Function Documentation

◆ bteToState()

◆ getEnergy()

◆ getGroupVelocity()

◆ getIndex() [1/2]

◆ getIndex() [2/2]

◆ getMaxEnergy()

◆ getNumBands() [1/2]

◆ getNumBands() [2/2]

◆ getNumPoints()

◆ getNumStates()

◆ getParticle()

◆ getPoint()

◆ getPointIndex()

◆ getPoints()

◆ getReducibleStarFromIrreducible()

◆ getRotationsStar() [1/2]

◆ getRotationsStar() [2/2]

◆ getRotationToIrreducible()

◆ getWavevector()

◆ hasWindow()

◆ irrPointsIterator()

◆ irrStateIterator()

◆ outputComponentsToJSON()

◆ parallelIrrPointsIterator()

◆ parallelIrrStateIterator()

◆ parallelStateIterator()

◆ printBandStructureStateInfo()

◆ setEigenvectors()

◆ setEnergies()

◆ setVelocities()

◆ stateToBte()