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Re: [abinit-forum] Determining the actual K points in density calculations

From: matthieu verstraete <matthieu.jean.verstraete@gmail.com>
To: forum@abinit.org
Subject: Re: [abinit-forum] Determining the actual K points in density calculations
Date: Thu, 6 Aug 2009 18:02:39 +0200
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you have used a shift for the first one, so the gamma point is not
calculated at all (this is fine, and possibly a better kpt grid for
density generation purposes). Set the shiftk to 0 0 0 and you should
check your first output file for the list of kpoints.

Matthieu

On Thu, Aug 6, 2009 at 3:41 PM, <davidmlove86@hotmail.com> wrote:
> Hello,
>
> I have done a convergence calculation of ecut using 4 kpt for a 10,0
> nanotube
> (see below: nt100.in). I then plotted the energy of the conduction band as a
> function of different ecut values for each of the k points. I did this by
> extracting the data from the produced eigenvalue files.
>
> Once I converged my input values I determined the conduction band structure
> using the density file from the previous converged calculation as an input
> (see
> below: nt100bands.in).
>
> However, I realized that the energy values of the conduction band structure
> plot do not equal the values of the energies at the same k points and band
> in
> the initial density calculation!
>
> I suspect that when abinit is going through the k points in the density
> calculation (nt100.in), that the first k point in the calculation is not
> actually the 0 k-point, i.e. (0,0,0).
>
> Could someone please tell me how I can determine the actual k points? Or
> even
> better, any thoughts on why the energy values of the same k point and in the
> same band do not equal each other in the density calculation (nt100.in) and
> in
> the band structure calculation (nt100bands.in)?
>
> Thank you.
>
> Regards,
> David
>
>
> ############################## nt100.in
> #####################################
> #ecut convergence for nt calc
>
> ndtset 8
>
> #Definition of the planewave basis set
> ecut: 5.0 ecut+ 5
>
> prteig 1
> prtden 1
> prtwf 1
>
> kptopt 1
> ngkpt 8 1 1
> nshiftk 1
> shiftk 0.5 0.0 0.0
> nkpt 4
>
> nband 100
>
> #Definition of the SCF procedure
> nstep 20 # Maximal number of SCF cycles
> toldfe 1.0d-6
> diemac 10
> diemix 0.33
>
> #definition of unit cell
> acell 0.80559E+01 0.80559E+01 0.80559E+01
> rprim # primitive cell definition
> 0.00000E+00 0.00000E+00 0.10000E+01
> 0.30000E+01 0.00000E+00 0.00000E+00
> 0.00000E+00 0.30000E+01 0.00000E+00
>
> #definition of atom types
> ntypat 1
> znucl 6
>
> #definition of basis
> natom 40
> typat 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
> 1
> 1 1 1 1 1 1 1
> 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
> xcart # cartesian co-ords of atoms (bohr radii)
> 0.74024E+01 0.00000E+00 0.00000E+00
> 0.70401E+01 0.22875E+01 0.67133E+01
> 0.70401E+01 0.22875E+01 0.40280E+01
> 0.59887E+01 0.43510E+01 0.26853E+01
> 0.59887E+01 0.43510E+01 0.00000E+00
> 0.43510E+01 0.59887E+01 0.67133E+01
> 0.43510E+01 0.59887E+01 0.40280E+01
> 0.22875E+01 0.70401E+01 0.26853E+01
> 0.22875E+01 0.70401E+01 0.00000E+00
> 0.00000E+00 0.74024E+01 0.67133E+01
> 0.00000E+00 0.74024E+01 0.40280E+01
> -0.22875E+01 0.70401E+01 0.26853E+01
> -0.22875E+01 0.70401E+01 0.00000E+00
> -0.43510E+01 0.59887E+01 0.67133E+01
> -0.43510E+01 0.59887E+01 0.40280E+01
> -0.59887E+01 0.43510E+01 0.26853E+01
> -0.59887E+01 0.43510E+01 0.00000E+00
> -0.70401E+01 0.22875E+01 0.67133E+01
> -0.70401E+01 0.22875E+01 0.40280E+01
> -0.74024E+01 0.00000E+00 0.26853E+01
> -0.74024E+01 0.00000E+00 0.00000E+00
> -0.70401E+01 -0.22875E+01 0.67133E+01
> -0.70401E+01 -0.22875E+01 0.40280E+01
> -0.59887E+01 -0.43510E+01 0.26853E+01
> -0.59887E+01 -0.43510E+01 0.00000E+00
> -0.43510E+01 -0.59887E+01 0.67133E+01
> -0.43510E+01 -0.59887E+01 0.40280E+01
> -0.22875E+01 -0.70401E+01 0.26853E+01
> -0.22875E+01 -0.70401E+01 0.00000E+00
> 0.00000E+00 -0.74024E+01 0.67133E+01
> 0.00000E+00 -0.74024E+01 0.40280E+01
> 0.22875E+01 -0.70401E+01 0.26853E+01
> 0.22875E+01 -0.70401E+01 0.00000E+00
> 0.43510E+01 -0.59887E+01 0.67133E+01
> 0.43510E+01 -0.59887E+01 0.40280E+01
> 0.59887E+01 -0.43510E+01 0.26853E+01
> 0.59887E+01 -0.43510E+01 0.00000E+00
> 0.70401E+01 -0.22875E+01 0.67133E+01
> 0.70401E+01 -0.22875E+01 0.40280E+01
> 0.74024E+01 0.00000E+00 0.26853E+01
>
>
>
> ############################ nt100bands.in #################################
> #Definition of the planewave basis set
> ecut 25.0
>
> prteig 1
> prtden 1
> prtwf 1
>
> iscf -2
> getden -1
> kptopt -1
>
> # kgrid
> ndivk 20
> kptbounds 0.0 0.0 0.0
> 1.0 0.0 0.0
> tolwfr 1.0e-12
> enunit 1
>
> nband 100
>
> #Definition of the SCF procedure
> nstep 20 # Maximal number of SCF cycles
> toldfe 1.0d-6
> diemac 10
> diemix 0.33
>
> #definition of unit cell
> acell 0.80559E+01 0.80559E+01 0.80559E+01
> rprim # primitive cell definition
> 0.00000E+00 0.00000E+00 0.10000E+01
> 0.30000E+01 0.00000E+00 0.00000E+00
> 0.00000E+00 0.30000E+01 0.00000E+00
>
> #definition of atom types
> ntypat 1
> znucl 6
>
> #definition of basis
> natom 40
> typat 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
> 1
> 1 1 1 1 1 1 1
> 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
> xcart # cartesian co-ords of atoms (bohr radii)
> 0.74024E+01 0.00000E+00 0.00000E+00
> 0.70401E+01 0.22875E+01 0.67133E+01
> 0.70401E+01 0.22875E+01 0.40280E+01
> 0.59887E+01 0.43510E+01 0.26853E+01
> 0.59887E+01 0.43510E+01 0.00000E+00
> 0.43510E+01 0.59887E+01 0.67133E+01
> 0.43510E+01 0.59887E+01 0.40280E+01
> 0.22875E+01 0.70401E+01 0.26853E+01
> 0.22875E+01 0.70401E+01 0.00000E+00
> 0.00000E+00 0.74024E+01 0.67133E+01
> 0.00000E+00 0.74024E+01 0.40280E+01
> -0.22875E+01 0.70401E+01 0.26853E+01
> -0.22875E+01 0.70401E+01 0.00000E+00
> -0.43510E+01 0.59887E+01 0.67133E+01
> -0.43510E+01 0.59887E+01 0.40280E+01
> -0.59887E+01 0.43510E+01 0.26853E+01
> -0.59887E+01 0.43510E+01 0.00000E+00
> -0.70401E+01 0.22875E+01 0.67133E+01
> -0.70401E+01 0.22875E+01 0.40280E+01
> -0.74024E+01 0.00000E+00 0.26853E+01
> -0.74024E+01 0.00000E+00 0.00000E+00
> -0.70401E+01 -0.22875E+01 0.67133E+01
> -0.70401E+01 -0.22875E+01 0.40280E+01
> -0.59887E+01 -0.43510E+01 0.26853E+01
> -0.59887E+01 -0.43510E+01 0.00000E+00
> -0.43510E+01 -0.59887E+01 0.67133E+01
> -0.43510E+01 -0.59887E+01 0.40280E+01
> -0.22875E+01 -0.70401E+01 0.26853E+01
> -0.22875E+01 -0.70401E+01 0.00000E+00
> 0.00000E+00 -0.74024E+01 0.67133E+01
> 0.00000E+00 -0.74024E+01 0.40280E+01
> 0.22875E+01 -0.70401E+01 0.26853E+01
> 0.22875E+01 -0.70401E+01 0.00000E+00
> 0.43510E+01 -0.59887E+01 0.67133E+01
> 0.43510E+01 -0.59887E+01 0.40280E+01
> 0.59887E+01 -0.43510E+01 0.26853E+01
> 0.59887E+01 -0.43510E+01 0.00000E+00
> 0.70401E+01 -0.22875E+01 0.67133E+01
> 0.70401E+01 -0.22875E+01 0.40280E+01
> 0.74024E+01 0.00000E+00 0.26853E+01
>

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dr. Matthieu Verstraete

European Theoretical Spectroscopy Facility (ETSF)
Dpto. Fisica de Materiales,
U. del Pais Vasco,
Centro Joxe Mari Korta, Av. de Tolosa, 72, Phone: +34-943018393
E-20018 Donostia-San Sebastian, Spain Fax : +34-943018390

Mail : matthieu.jean.verstraete@gmail.com
http://www-users.york.ac.uk/~mjv500

[abinit-forum] Determining the actual K points in density calculations, davidmlove86, 08/06/2009
- Re: [abinit-forum] Determining the actual K points in density calculations, matthieu verstraete, 08/06/2009