Silicene bandstructure calculation

[huckelbuckel]

thanks a lot for this info..

[Anders Blom]

It's interesting that there are multiple minima, it might explain why it can be hard for the optimization routine to find the global minimum, it might get stuck in a local one. As I mentioned before, it's not only a matter of angle - for each angle the bond length may change, so it's a two-dimensional minimization problem. When comparing to literature values, one must compare apples and apples For instance, LDA cannot be compared to GGA, they are expected to give different results. So one cannot just say "literature value is ...", at least not for a quantity like this. To rotate in Python (NOTE: This is not an officially supported method. It may not work, now or in the future some day. It does work in 11.8 however.)

Code: python

from NL.CommonConcepts.Configurations.Utilities import rotate
configuration = BulkConfiguration(...)

# Rotation angle, in Degrees
angle = 10.
# Axis is normalized internally
axis = [1,0,0]
# Rotate all atoms
indices = range(len(configuration.elements()))
# Rotation center
u0 = [0,0,0]*Angstrom
# Rotation updates configuration
rotate(configuration,indices,angle,axis,u0)

[huckelbuckel]

yes generally GGA calculated lattice values tend be higher than LDA  ones and there might be differences in the values because of different simulation packages that people use.... thanks for the code snippet.

But i still don't understand how the bond lengths will change on rotation as i only change the angle and even after rotating about y axis (say, 1degree,2 degree and so on..) i have checked in z-matrix the bond lengths remains the same as selected earlier.

see the attached image( 0 degrees and after rotation by 10 degrees )as the second atom gains some 'z ' coordinate as well
pls note i just calculated energy at each such 'new points' after rotation steps without including any kind of optimization.

Thanks for all the help given by forum members and moderators..and yesss wishing a very happy new year

[huckelbuckel]

correction: the second attached image is of rotation at 20degrees not 10.