ngkpt & nkpt

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Amal Giri
Posts: 9
Joined: Tue Mar 01, 2011 5:00 am

ngkpt & nkpt

Post by Amal Giri » Sat Apr 30, 2011 8:32 pm

Respected All,
Could anybody help me how
ngkpt 2 2 2
ngkpt 4 4 4
ngkpt 6 6 6
ngkpt 8 8 8
are correspond to
nkpt 2
nkpt 10
nkpt 28
nkpt 60
respectively? Please suggest me any study material on this topic.

With Best Regards
Amal

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jzwanzig
Posts: 504
Joined: Mon Aug 17, 2009 9:25 am

Re: ngkpt & nkpt

Post by jzwanzig » Sun May 01, 2011 12:40 pm

For a good overview on this topic and many others, see the book by RM Martin, Electronic Structure, Cambridge. Basically ngkpt together wtih nshiftk and shiftk are selecting the parameters of a Monkhorst-Pack grid of points in k space. Then, based on the value of kptopt, symmetry is used to reduce this set. The result is the number (nkpt) of k points actually used in the calculation, the effect of the symmetry related points that are not used explicitly is included through the effective weight of each point, which is determined internally.
Josef W. Zwanziger
Professor, Department of Chemistry
Canada Research Chair in NMR Studies of Materials
Dalhousie University
Halifax, NS B3H 4J3 Canada
jzwanzig@gmail.com

nouria.aouail
Posts: 8
Joined: Thu May 16, 2013 2:15 pm

Re: ngkpt & nkpt

Post by nouria.aouail » Sun Oct 19, 2014 4:15 pm

hello, what's to say ngkpt = 4 4 1 ?

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