[Pw_forum] special points mesh

[Paolo Giannozzi]

On Friday 30 May 2003 12:56, ilyes hamdi wrote:
> Dear Users
> In PWSCF we use six parameters to generate special
> points in Monkhorst-Pack method. the 3 last parameters
> are defined to be 0 or 1. What's the meaning of these

k-point grid offset along the 3 crystal axis (in reciprocal
space)

> and where can i find their definition in the program.

The definition is in PW/kpoint_grid.f90

> Last year i worked on CASTEP, and i have only to
> define the grid nk1,nk2,nk3. exemple
> structure ZB
> 4x4x4 gives 10 points in CASTEP is equivalent to
> 4x4x4 001 in PWSCF.

equivalent to "4 4 4 0 0 0", I guess.

k1 = 0 means no offset in the 1 direction, k1 = 1 means that
the k-point grid is translated by one-half of the grid step in 
the 1 direction : G_1 /(2*nk1). Same on directions 2 and 3.

Paolo

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Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
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