[Pw_forum] k-point grids...and all that

[Paul M. Grant]

This post is mainly a question regarding available resources in "o-sesame
CVS or espresso-4.0" enabling calculation of "k-point," or "k-space"
volumetric grids within the first Brillouin Zone of a given real space
structure for use in the computation of various "post-processing"
applications in the PWscf package (including pwtools, e.g., Fermi surface
and optical properties).

The ability to compute weighted 1st BZ grids according to the Monkhorst-Pack
scheme is included somewhere within espresso-4.0, but exactly where is
unclear (k-points.f90?  No).  (Sure, I can fake it with an appropriate *.in
input to pw.x)  The nearest I find is Eyvaz Isaev's kvect_FS.f which (seems
to) compute a volumetric grid (unweigted) for subsequent Fermi surface
determination (Is the output symmetrized?  I.e., does the code at least
account for inversion symmetry?)

Now, how do I compute the "grid" to input to a tool such as epsilon.x, e.g.,
like grid.data for the example of aluminum?  And what about the "60-point"
grid for Ni in Example 08?  With or without MP weighting.

Finally, is there a visualization tool to display the k-point distribution
within the  1st BZ?  XcrysDen?

Paul M. Grant, PhD
Principal, W2AGZ Technologies
Visiting Scholar, Applied Physics, Stanford (2005-2008)
EPRI Science Fellow (Retired)
IBM Research Staff Member Emeritus
w2agz at pacbell.net
http://www.w2agz.com <http://www.w2agz.com/> 
 
 


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