Parameters for calculating complexBandStructure¶

Parameters here are for calculating the complex band structure.

calculation.complexBandStructure.whatDirection¶

key word	:	calculation.complexBandStructure.whatDirection
possible values	:	1, 2, or 3
default value	:	3
description	:	when performing complex-band structure calculation, one
		and only one of the three fractional coordinates of
		wave vectors, k1, k2, and k3, is allowed to be a complex
		number, while the other two are real.
		whatDirection is used to indicate the complex one. e.g.,
		whatDirection = 2 means that k2 can be a complex number
		while k1 and k2 are kept real.

		The complex-band structure can be expressed as
		k_para = k_para(e,k_tran)
		where k_para is the complex component of the wave vector
		and e the band energy, k_tran the transverse components
		of the wave vector. The corresponding complex k-vector is
		k-vector = k1\(\times\)b1 + k2\(\times\)b2 + k3\(\times\)b3,
		where b1, b2, and b3 are defined through
		dot(b_i, a_j) = 2\(\pi\)\(\times\)\(\delta_{ij}\),
		and a1, a2, a3 are the central cell vectors defined
		in centralCellVectors.
an example	:	calculation.complexBandStructure.whatDirection = 3

key word	:	calculation.complexBandStructure.kSpaceGridNumber
possible values	:	3\(\times\)1 integer array
default value	:	[1 1 1]
description	:	the small k-space grid number in each direction which,
		together with kSpaceGridShift, is used to produce the
		parameter kSpacePoints.
an example	:	calculation.complexBandStructure.kSpaceGridNumber = …
		[10 10 10]

key word	:	calculation.complexBandStructure.kSpaceGridShift
possible values	:	3\(\times\)1 or 1\(\times\)3 array, [s\(_1\), s\(_2\), s\(_3\)], with each s\(_i\) a
		double number between 0 and 1.
default value	:	[0 0 0]
description	:	k-space grid point shift. While all s\(_i\) are set to be 0,
		the Gamma point is always among the k-space grid points
		being generated; otherwise, the k-space grid points will
		be shifted s\(_1\), s\(_2\), and s\(_3\) grid length along their
		grid vector directions, respectively.
an example	:	calculation.complexBandStructure.kSpaceGridShift = …
		[1/2 1/2 1/2]

key word	:	calculation.complexBandStructure.kSpacePoints
possible values	:	3\(\times\)n double array
default value	:	produced by parameter kSpaceGridNumber if it is given,
		otherwise, [0 0 0] (i.e. gamma point only)
description	:	the fractional coordinates of n transverse wave vectors
		at which the complex-band structure will be calculated.
an example	:	calculation.complexBandStructure.kSpacePoints = [0 0 0]

key word	:	calculation.complexBandStructure.energyRange
possible values	:	a 2\(\times\)1 double array
default value	:	no default value
description	:	this parameter and numberOfEnergyPoints are used to
		produce the parameter energyPoints.
		Note that its values are measured from the Fermi energy.
an example	:	calculation.complexBandStructure.energyRange = [-10,10]

key word	:	calculation.complexBandStructure.numberOfEnergyPoints
possible values	:	an integer number
default value	:	no default value
description	:	this parameter and energyRange are used to
		produce the parameter energyPoints.
an example	:	calculation.complexBandStructure.numberOfEnergyPoints …
		= 100

key word	:	calculation.complexBandStructure.energyPoints
possible values	:	n\(\times\)1 double array with n an integer
default value	:	determined by energyRange and numberOfEnergyPoints if
		they are both given, otherwise 0.
description	:	the energy points at which the the complex-band
		structure is to be calculated.
an example	:	calculation.complexBandStructure.energyPoints = -10:0.1:10

key word	:	calculation.complexBandStructure.plot
possible values	:	true or false
default value	:	false
description	:	If true, a plot will be given after the calculation.
		In the plot, k is the wave vector for Bloch waves, and
		\(\kappa\) is the imaginary part of the wave vector for
		evanescent waves.
an example	:	calculation.complexBandStructure.plot = true

key word	:	calculation.complexBandStructure.fullplot
possible values	:	true or false
default value	:	false
description	:	If true, both positive and negative \(\kappa\) are plotted,
		otherwise, only negative \(\kappa\) are plotted.
an example	:	calculation.complexBandStructure.fullplot = true