cbs keywords

Complex band structure calculator

cbs.whatDirection

When performing complex-band structure calculation, one and only one of the three fractional coordinates of wavevectors, 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 x b1 + k2 x b2 + k3 x b3, where b1, b2, and b3 are defined through dot(b_i, a_j) = 2pi x delta_{i,j}, and a1, a2, a3 are the central cell vectors defined in centralCellVectors.

type: scalar

default: 3

size: 1

example: calculation.cbs.whatDirection = 3

cbs.energyRange

This parameter and numberOfEnergyPoints are used to produce the parameter energyPoints. Note that its values are measured from the Fermi energy.

type: array

size: [1,2]

example: cbs.energyRange = [-10, 10]

cbs.numberOfEnergyPoints

This parameter and energyRange are used to produce the parameter energyPoints.

type: scalar

default: 100

example: cbs.numberOfEnergyPoints = 200

cbs.energyPoints

Determined by energyRange and numberOfEnergyPoints if they are both given, otherwise 0.

type: array

size: [inf, 1]

example: cbs.energyPoints = linspace(-10,10,101)

cbs.plot

If true, a plot will be given after the calculation. In the plot, k is the wavevector for Bloch waves, and kappa is the imaginary part of the wavevector for evanescent waves.

type: scalar

default: false

example: cbs.plot = true