[Pw_forum] Monkhorst Pack k points

[Cyrille Barreteau]

Ok so you are not using the "original" Monkhorst-Pack grid but a slightly
modified version always centered on the Gamma point (if  j1=j2=j3=0).

thanks
    cyrille

>On Tuesday 30 May 2006 11:39, Cyrille Barreteau wrote:
>
>  
>
>>I am generating the k points by the following input:
>>
>>K_POINTS automatic
>>n1 n2  1 0 0 0
>>
>>According to the manual the code is using MP k points but I am a bit
>>surprised to find that the Gamma= 0,0,0  point is always present in 
>>the k points list whatever the parity of the integers n1 and n2.
>>    
>>
>
>K_POINTS automatic
>  n1 n2 n3 j1 j2 j3
>yields a grid of k-points:
>  k(i1,i2,i3)  = (i1+j1/2) * g1/n1 + (i2+j2/2) * g2/n2 + (i3+j3/2) * g3/n3
>where g1, g2, g3 are the vectors that generate the reciprocal lattice;
>the indices i1, i2, i3, run from 0 to n1-1, n2-1, n3-1 respectively;
>j1, j2, j3 can be either 0 (no offset, k=0 in the grid) or 1 (with offset,
>k=0 not in the grid). What is usually referred to as "Monkhorst-Pack" 
>grid has offset and does not contain k=0 . Of course, only inequivalent
>k-points are actually used
>
>Paolo
>  
>


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Cyrille Barreteau

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