Hello everyone,
Iam done with the band strucutre calculations ad I got the practice material online but I want to understand about the input file for plotband.x.
So please make me understand that how to choose these values in plotband.in or what these values signify?
The file is below:
Sibands.dat
-6.0 20 //How to choose these value and what it signify
Si.xmgr
Si.ps
6.255 //How to choose these value and what it signify
1.0 6.255 // How to choose these value and what it signify
Please make me understand so that I can generate my own plotband.in .
Thanks,
Abhinav
Hello Abhinav
First line (-6.0 20) is for specifying minimum and maximum energy range on the plot (on the y axis)
6.255 is Fermi energy taken from pw.x
Next in last marked line the 1.0 is delta E - the smallest step in energy (y axis tics) and 6.255 is value which will be marked as zero on the plot, again energy axis (just put here Fermi value, so the 0 mark on the plot will be at Fermi energy).
Hope this helps.
Hello Abhinav
First line (-6.0 20) is for specifying minimum and maximum energy range on the plot (on the y axis)
6.255 is Fermi energy taken from pw.x
Next in last marked line the 1.0 is delta E - the smallest step in energy (y axis tics) and 6.255 is value which will be marked as zero on the plot, again energy axis (just put here Fermi value, so the 0 mark on the plot will be at Fermi energy).
Hope this helps.
Hi,
I am sorry to contradict Konrad, but the first two value are the energy range in the y axis: so you don't plot all the bands but only a window of values between these two extremes. Also delta E is the energy ticks on the y axis.
Notice that the delta E and energy reference values are used only for the plot in postscript form (Si.ps), while Si.xmgr contains the raw data (although limited in the region specified) of the bands and might be useful for plotting with other programs.
Also, plotbands.x can be run interactively so you do not need to remember all this. With recent versions of quantum espresso, bands.x also produces an output file which can be plotted with gnuplot (or similar), but beware since energies there are in Rydberg.
Cheers,
Roberto
Thank you Roberto for your kindly comment, of course you are 100% right, in my above post (I don't know why) I written x axis while I of course meant 'y' all the time...
Generally speaking everything is true, but when you change axis. I should just not specify the axis names at all, cause everyone has their own favorite way to show figures.
I think that I should change this in previous post, for the clarity.
Konrad
What is that header file? In this example, what is Sibands.dat and where to get it from? Is it the .out file from nscf_bands (bands.x) calculation? Is it always in .dat format? I don't understand it.
Dear Bharat,
Yes, the file you should process is the output produced by bands.x (the output file) specified in the input file of bands.x. This is processed by plotband.x. You are free to chose the name of it (so feel free to add a .dat extension but this is not necessary) in the input file of bands.x. However, notice that the new version of bands.x are already prodicing a file with extension .gnu that one can plot easily with gnuplot or any other plotting program. So the use of plotbands.x is not strictly speaking necessary.
hi
dose anyone get this error?:
Error in routine plotband (1):
too many lines
I do not know what to do! if I decrease my nks then the bandstructure is not usefull anymore and it shows nothing
have you looked at QE reference pages? How many high symmetry points are you considering? Do you mind sharing you input files?
regards,
roberto
Roberto D'Agosta and Asiye Shokri , did you get the solution to this error? I got the same when running 'plotband.x' immmediatelly i enter the range.
Error in routine plotband (1):
too many lines
You might want to have a look at this
https://lists.quantum-espresso.org/pipermail/users/2013-November/028039.html
While for sure you have less than 99 high symmetry points, some of them might be repeated.did you try to use for example only the points with 0 in the vertical axes?
Regards,
roberto
Roberto D'Agosta, thank you for your previous contributions to this post, very informative. I'll add one more question to the thread if you don't mind.
You say that plotband.x is not needed since bands.x already outputs a gnuplot friendly file. I fully agree, and that's how I've always plotted band structures.
However, I now want to plot projected (so called "fat") bands. From what I can see online, I'd need plotband.x in that case. There's no way around it, right? or is there a way to do that with only bands.x?
Cheers!
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