kappa in complex band structure

[BM]

Could you please let me know how the "kappa" axis is  generated from the reciprocal cartesian coordinates in complex band structure. In the online documentation. `the complex k is multiplied with (L/pi where L=a/2) in 3D visualisation but not in case of 2D visualistaion  Why is it so?I However, the reference journal in the documentation shows that both imaginary and real k are in terms of (2pi/a). I am extracting the complex band structure data to use for fitting with some analytical CBS dispersion.  How should I project the imaginary k from my analytical calculations to fit with  CBS extracted from ATK. I ask this as I am a bit confused about the multiplication factor (L/pi).

[Petr Khomyakov]

Which version of QuatumATK are you using? In QuantumATK 2018, both 2D and 3D visualization of the complex band structure give the real part of k-vector in fractional coordinates (L/pi), whereas the imaginary part is in Cartesian (1/Angstrom), as described in the manual, https://docs.quantumwise.com/manual/Types/ComplexBandstructure/ComplexBandstructure.html. 

If you want to use different units for the k-vector, you may multiply it by the corresponding factor. The k-points and energies for which the complex band structure was calculated can be obtained from the complex band structure object, see the manual https://docs.quantumwise.com/manual/Types/ComplexBandstructure/ComplexBandstructure.html.