[Pw_forum] why is the tetrahedron interpolated DOS step-like?

[Eduardo Ariel Menendez Proupin]

>Eduardo: you may want to rehearse the theory of critical points, such as explained in many solid-state texts, my favorite one (at least in this field) still being Bassani and Pastori Parravicini's. SB
Stefano,
Thank you. You are right if the system is 2D, but in this case it is
quasi-1D. The 1-D Van Hove singularitu is appreciated in the large
energy scale of the
plot between -6 and -4 eV.

Maybe the steps in the low energy scale reveal that a quasi-1D system
with a finite k-point sampling is an effective bi-dimensionality with
a smaller energy scale, with as many bands as k-points. I do not think
that you are meaning that,
as k-points sampling is not a matter of solid state textbooks.

Thanks, and nice weekend
Eduardo

On Dec 9, 2011, at 1:33 PM, Eduardo Ariel Menendez Proupin wrote:

>* Dear all,*>* *>* I would like to know if the step-like aspect of a DOS calculated with the tetrahedron interpolation is what is expected to be. Please, take a look at the figures attached. I would expect something soft or at least a polygonal line with slope. *>* *>* I have looked at flib/dost.f90 and checked that the interpolation formulae are the same of the Bloechl's article OK.*>* I am sorry to ask such a basic question, but I am puzzled since a long time, and tired of soften the stepped line with an additional program. *>* Thanks in advance*



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