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XML QP band file missing lines
Laurent Chapon (guest) 27 May 2019 11:45
in discussion Forum / Support Questions » XML QP band file missing lines

Dear exciting team,
I have seen that the bandstructure-qp.xml file created after a GW calculation is missing two lines at the end of the file
</band> and </bandstructure>.
It would be nice also if the vertex could be written in a similar way than for the KS bandstructure.xml

All the best.

XML QP band file missing lines by Laurent Chapon (guest), 27 May 2019 11:45
Laurent Chapon (guest) 26 May 2019 09:30
in discussion Forum / Support Questions » Spectral function plot

Hi Dmitrii,
I have been playing with this, removing the lines as indicated and recompiling does the trick, now the spectral function is written to file for all irreducible k-points.
However, I am struggling to find a correspondence between the quasiparticle band energies (which are as expected when I plot the band structure of DFT@G0W0) and the output written in SpectraFunction.dat
I have tried for a simple hexagonal BN system below:

<structure speciespath="/apps/contrib/dls-spectroscopy/exciting/nitrogen-intel2018/species">
<crystal scale="1.88972687777">
<basevect>2.5200000000 0.0000000000 0.0000000000</basevect>
<basevect>-1.2599999999999993 2.1823840175367857 0.0000000000</basevect>
<basevect> 0.0000000000 0.0000000000 6.66000000000000</basevect>
</crystal>
<species speciesfile="B.xml" rmt="1.35">
<atom coord="0.0000000 0.0000000 0.00"></atom>
<atom coord="0.0000000 0.0000000 0.50"></atom>
</species>
<species speciesfile="N.xml" rmt="1.35">
<atom coord="0.3333333 0.666666666 0.00"></atom>
<atom coord="0.6666666 0.333333333 0.50"></atom>
</species>
</structure>

by Laurent Chapon (guest), 26 May 2019 09:30

Ups! I've just realized that it is hardcoded to print only the first (Gamma) point.
The solution would require to remove lines 272, 273 in src/src_gw/plot_selfenergy.f90 and recompile the code.

by DmitriiNabokDmitriiNabok, 22 May 2019 13:11
Laurent Chapon (guest) 22 May 2019 10:22
in discussion Forum / Support Questions » Spectral function plot

The structure of the File SpectralFunction.dat contains indeed the frequency and then (nbgw-ibgw) columns but irrespective of the grid I choose, the information seems to be written only for # ik = 1 which I guess is only the first irreducible point.
I must be doing somehting wrong.

by Laurent Chapon (guest), 22 May 2019 10:22
Laurent Chapon (guest) 21 May 2019 09:56
in discussion Forum / Support Questions » Spectral function plot

Thanks Dmitrii,
Workaround would be good :) but for the moment I will go for dense grids.

by Laurent Chapon (guest), 21 May 2019 09:56

Hi Laurent,

That'd indeed be great to plot An(k,w) along a path… But unfortunately, due to some specifics of the implementation, it's not so straightforward. At the moment, the only solution I could suggest (and what I'm actually using) is to try to compute GW with as dense as possible k-grids and extract the required k-path points manually.

There are, however, some other workaround approaches we could try ;-)
Best,
Dmitrii

by DmitriiNabokDmitriiNabok, 21 May 2019 06:33
Laurent Chapon (guest) 20 May 2019 21:18
in discussion Forum / Support Questions » Spectral function plot

Spectral function works fine, thanks a lot for the help.
Is there any way to cacluclate An(k,w) along specific k directions, as for example set by taskname "band". ?
properties>
<bandstructure>
<plot1d>
<path steps="100">
<point coord=" 0.750 0.500 0.250" label="W"/>
<point coord=" 0.500 0.500 0.500" label="L"/>
<point coord=" 0.000 0.000 0.000" label="GAMMA"/>
<point coord=" 0.500 0.500 0.000" label="X"/>
<point coord=" 0.750 0.500 0.250" label="W"/>
<point coord=" 0.750 0.375 0.375" label="K"/>
</path>
</plot1d>
</bandstructure>
<dos
winddos="-0.5 0.5"
nwdos="200"
></dos>
</properties>

by Laurent Chapon (guest), 20 May 2019 21:18
Laurent Chapon (guest) 20 May 2019 20:13
in discussion Forum / Support Questions » Spectral function plot

Sorry, my bad, it worked.

by Laurent Chapon (guest), 20 May 2019 20:13
Laurent Chapon (guest) 20 May 2019 19:58
in discussion Forum / Support Questions » Spectral function plot

Hi Dmitrii,
is taskname ="sepl" available in nitrogen. I have an error when using it.

by Laurent Chapon (guest), 20 May 2019 19:58
Laurent Chapon (guest) 20 May 2019 18:22
in discussion Forum / Support Questions » Spectral function plot

Hi Dmitrii,
thanks a lot, will give it a go. Definitely interested in testing the new features when they will become available (interested in simulating photoemission experiments which require the spectral function as well as matrix elements in the dipole approximation), I will contact you directly.

by Laurent Chapon (guest), 20 May 2019 18:22

Hi,

Thanks for using exciting and positive feedback!!!
Frankly speaking, "spectralfunctionplot" in the current version is not 100% reliable and should be treated as "under development". Therefore I did not intend to make it visible :-) Although you may still try to use it. For this, you should first complete "g0w0" task first.
And after that, one needs just to switch the task to:

taskname="sepl"

and specify parameters for the plot:
<selfenergy
actype="pade"
singularity="mpb"
>
<SpectralFunctionPlot
axis="real"
nwgrid="1000"
wmin="-2.0"
wmax="1.0">
</SpectralFunctionPlot>
</selfenergy>

This should generate a group of files. The spectral function data is in "SpectralFunction.dat"
For each irreducible k-point, the An(k,w) is printed in a format convenient for visualization, e.g., with GnuPlot:
first column - w
2, 3, … columns - states from "ibgw" to "nbgw"

FYI, I'm about to make public a new version of GW code with a bunch of new features. One of them is a more precise treatment of the frequency dependency (W(w), A(w), Sigma(w)). Please contact me directly, if you're interested in testing new features before the new release.

Best regards,
Dmitrii
(the exciting developer team)

Spectral function plot
Laurent Chapon (guest) 20 May 2019 14:13
in discussion Forum / Support Questions » Spectral function plot

I am looking for an example input file or a tutorial to plot the spectral function from a GW calculation.
The input reference mentions spectralfunctionplot, but I have not been able to find it used in the tutos.

Thanks in advance, and congrats to all of the developers for the great work, exciting is great and easy to use, I am really impressed.

Spectral function plot by Laurent Chapon (guest), 20 May 2019 14:13

Dear Zeyu Jiang,

you did everything right. For these calculations in exciting it is assumed that the first entry in the list of q-points corresponds to Gamma. If this does not happen, the code stops.

Best regards,
Caterina Cocchi
(exciting team)

Dear developers:

I'm calculating the exciton dispersion of a 2D honeycomb lattice material. I first calculated the dispersion along Gamma-K and Gamma-M paths with:
iqmtrange="1 5"
<qpointset>
<qpoint>0.0000000 0.0000000 0.0000000</qpoint>
<qpoint>0.0833333 0.0833333 0.0000000</qpoint>
<qpoint>0.1666667 0.1666667 0.0000000</qpoint>
<qpoint>0.2500000 0.2500000 0.0000000</qpoint>
<qpoint>0.3333333 0.3333333 0.0000000</qpoint>
</qpointset>
and
iqmtrange="1 6"
<qpointset>
<qpoint>0.0000000 0.0000000 0.0000000</qpoint>
<qpoint>0.0000000 0.1000000 0.0000000</qpoint>
<qpoint>0.0000000 0.2000000 0.0000000</qpoint>
<qpoint>0.0000000 0.3000000 0.0000000</qpoint>
<qpoint>0.0000000 0.4000000 0.0000000</qpoint>
<qpoint>0.0000000 0.5000000 0.0000000</qpoint>
</qpointset>
all the two runs are finished successfully and give reasonable results. However, when I turned the the K-M path with
iqmtrange="1 5"
<qpointset>
<qpoint>0.3333333 0.3333333 0.0000000</qpoint>
<qpoint>0.2500000 0.3750000 0.0000000</qpoint>
<qpoint>0.1666667 0.4166667 0.0000000</qpoint>
<qpoint>0.0833333 0.4583333 0.0000000</qpoint>
<qpoint>0.0000000 0.5000000 0.0000000</qpoint>
</qpointset>
I found that the job can not even start, i.e., it directly exits with INFOXS.OUT file containing only a title

| EXCITING NITROGEN started for task xsgeneigvec (301) =
| version hash id: =
| MPI version using 24 processor(s) =
| | using MPI-2 features =
| =
| Date (DD-MM-YYYY) : 18-05-2019 =

But, if I arbitrarily include Gamma point (0,0,0) in qpointset
iqmtrange="1 6"
<qpointset>
<qpoint>0.0000000 0.0000000 0.0000000</qpoint>
<qpoint>0.3333333 0.3333333 0.0000000</qpoint>
<qpoint>0.2500000 0.3750000 0.0000000</qpoint>
<qpoint>0.1666667 0.4166667 0.0000000</qpoint>
<qpoint>0.0833333 0.4583333 0.0000000</qpoint>
<qpoint>0.0000000 0.5000000 0.0000000</qpoint>
</qpointset>
then everything seems to go right.

(of course, I used the same value for other parameters in all the tree calculations above)

I really want to know whether this is normal for exciting. Or did I do something wrong?

Thanks very much for your help~

Zeyu Jiang
PhD Student
Department of Physics, Tsinghua University

Re: Installation
TarsaTarsa 15 May 2019 13:19
in discussion Forum / Controversy » Installation

Hey
Try to find the solution for your problem and particular software on Google…


Custom software development company

Re: Installation by TarsaTarsa, 15 May 2019 13:19

Hi everybody!
Currently, the 'lonly' attribute has only an impact on PDOS calculated using Wannier interpolation. In about one month, we will release an updated version of exciting Nitrogen with this option also implemented in the standard PDOS.

Thanks for your comments :)
Sebastian

by Sebastian TillackSebastian Tillack, 08 May 2019 08:42
lonly
diego (guest) 07 May 2019 15:41
in discussion Forum / Controversy » lonly

Element DOS with attribute lonly doen't work , please help

lonly by diego (guest), 07 May 2019 15:41
Diego (guest) 07 May 2019 15:39
in discussion Forum / Support Questions » PDOS with attribute lonly

Hi, i have the same problem, you could fix it?

by Diego (guest), 07 May 2019 15:39
lonly
Diego (guest) 06 May 2019 04:18
in discussion Forum / Support Questions » lonly

Element DOS with attribute lonly doen't work , please help

lonly by Diego (guest), 06 May 2019 04:18
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