<div dir="ltr">Thanks for responding. Yes, also without adaptive smearing the results differ a little bit. However, the difference decreases with k-mesh size. With dos_kmesh 10 the difference is very small and with lower values the results are identical.<div><br></div><div>For debugging purposes, I tried dos_kmesh 2 with adaptive smearing. If I put</div><div><div><br></div><div> 8</div><div> 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.12500</div><div> 5.00000000E-01 0.00000000E+00 0.00000000E+00 0.12500</div><div> 0.00000000E+00 5.00000000E-01 0.00000000E+00 0.12500</div><div> 5.00000000E-01 5.00000000E-01 0.00000000E+00 0.12500</div><div> 0.00000000E+00 0.00000000E+00 5.00000000E-01 0.12500</div><div> 5.00000000E-01 0.00000000E+00 5.00000000E-01 0.12500</div><div> 0.00000000E+00 5.00000000E-01 5.00000000E-01 0.12500</div><div> 5.00000000E-01 5.00000000E-01 5.00000000E-01 0.12500</div></div><div><br></div><div>into my kpoint.dat, then I get the correct result. However, with</div><div><br></div><div><div> 3</div><div> 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.12500</div><div> 5.00000000E-01 0.00000000E+00 0.00000000E+00 0.50000</div><div> 5.00000000E-01 5.00000000E-01 0.00000000E+00 0.37500</div></div><div><br></div><div>the results again differ. (I forgot to say that NaI has the rock-salt structure.)</div><div><br></div><div>I had a look at the loop that performs the main calculation in dos_main and inserted</div><div><br></div><div> write(*,'(*(f7.5,1x))') kpt, dos_k(452,1)*kweight<br></div><div><br></div><div>after the 'dos_all=dos_all+dos_k*kweight' line to see how each k-point contributes to the sum. Here the index 452 refers to some energy level that I randomly picked. The result is</div><div><br></div><div><div> 0.00000 0.00000 0.00000 0.22149</div><div> 0.00000 0.00000 0.50000 4.22194</div><div> 0.00000 0.50000 0.00000 3.32614</div><div> 0.00000 0.50000 0.50000 0.00000</div><div> 0.50000 0.00000 0.00000 1.11124</div><div> 0.50000 0.00000 0.50000 0.00000</div><div> 0.50000 0.50000 0.00000 0.00000</div><div> 0.50000 0.50000 0.50000 0.45465</div></div><div><br></div><div>where the last column is the corresponding density. By symmetry, I would expect only 3 numbers to differ in this column, but this is not the case. Have I misunderstood something?</div><div><br></div><div>As another check, before the main loop, I put</div><div><br></div><div><div> kpt = [0.5,0.0,0.0]</div><div> call get_eig_deleig(kpt, eig, del_eig, HH, delHH, UU)</div><div> print*, norm2(del_eig(1,:))</div><div> kpt = [0.0,0.5,0.0]</div><div> call get_eig_deleig(kpt, eig, del_eig, HH, delHH, UU)</div><div> print*, norm2(del_eig(1,:))</div></div><div><br></div><div>which prints the magnitude of the band derivative of the first band at these two k-points, with the result</div><div><br></div><div><div> 0.44616527636129560 </div><div> 3.1348138571982227E-003</div></div><div><br></div><div>Shouldn't these numbers be the same by symmetry?</div><div><br></div><div>Finally, I'm not sure what you mean by '<span style="font-size:12.8000001907349px">units for the kpoints' as I'm only entering the reduced coordinates.</span></div><div><br></div><div>Raul</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Dec 12, 2014 at 5:38 PM, Giovanni Pizzi <span dir="ltr"><<a href="mailto:giovanni.pizzi@epfl.ch" target="_blank">giovanni.pizzi@epfl.ch</a>></span> wrote:<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Dear Raul,<br>
in order to understand if the problem is in the dos routine, or in
the routine that generated the IBZ points, could you run the same
thing (i.e. DOS, with and without wanint_kpoint_file), but using
dos_adpt_smr=False, and instead a fixed-width smearing? (e.g. a
gaussian smearing)<br>
And then compare the results, and report them here?<br>
<br>
As a further detail, could you also check if the units for the
kpoints that you are passing in the wanint file are the one
expected by the code?<br>
<br>
Thanks,<br>
Giovanni<div><div class="h5"><br>
<br>
<br>
On 12/12/2014 11:09 AM, Raul Laasner wrote:<br>
</div></div></div>
<blockquote type="cite"><div><div class="h5">
<div dir="ltr">Dear all,
<div><br>
</div>
<div>When I calculate the density of the lowest conduction
states of NaI (see attachment), I get different results for
using k-points from the full and irreducible Brillouin zones.
The difference is smaller when the k-mesh is allowed to use
less symmetries, e.g. only the time reversal symmetry. There
is no difference if the 'kpoint.dat' file contains the full
BZ. This suggests the code I use for generating IBZ points
might be in error, but I get the same results with both abinit
and elk (they deliver different, but equivalent IBZ points).
Could it be that the DOS calculation is very sensitive to
small numerical inaccuracies and this leads to slightly
different results for full and irreducible BZs? The DOS
related part of my input file is the following:</div>
<div><br>
</div>
<div>
<div>dos true</div>
<div>dos_kmesh 20</div>
<div>dos_adpt_smr true<br>
</div>
<div>wanint_kpoint_file false # true for the second run<br>
</div>
</div>
<div><br>
</div>
<div>The difference is also present with dos_kmesh 50. Please
ask for other details I'm not showing. Any suggestions are
welcome.</div>
<div><br>
</div>
<div>Thanks,</div>
<div>Raul Laasner</div>
<div><br clear="all">
<div><br>
</div>
-- <br>
<div>
<div dir="ltr">Raul Laasner<br>
Institute of Physics<br>
University of Tartu<br>
Ravila 14c, 50411, Estonia<br>
e-mail: <a href="mailto:raullaasner@gmail.com" target="_blank">raullaasner@gmail.com</a><br>
cell: <a href="tel:%28%2B372%295182268" value="+3725182268" target="_blank">(+372)5182268</a></div>
</div>
</div>
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<br>
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<pre cols="72">--
Giovanni Pizzi
Post-doctoral Research Scientist
EPFL STI IMX THEOS
MXC 340 (Bâtiment MXC)
Station 12
CH-1015 Lausanne (Switzerland)
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<br></blockquote></div><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr">Raul Laasner<br>Institute of Physics<br>University of Tartu<br>Ravila 14c, 50411, Estonia<br>e-mail: <a href="mailto:raullaasner@gmail.com" target="_blank">raullaasner@gmail.com</a><br>cell: (+372)5182268</div></div>
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