Can anybody explain detailed procedure to calculate Band Structure using HSE functional. I tried with what it is written in VASP wiki but it did not work.
It works what is written in Wiki, HSE06. However, the calculation is very much expensive, especially when k-points are high. Please use 4x4x4 mesh and try it again.
@Pradeep R.Varadwaj: Thanks for your answer. Do i need to have preconverged WAVECAR with HSE method before calculating Band Structure or i can have from simply GGA method. I used automatic mesh of 17 17 10 with Gamma Centered as my system is hexagonal.
Actually, I have worked on a small system (12 atoms) with a 6x6x6 k-mesh grid. The system investigated was having cubic symmetry. I have used the following tags for the HSE06 calculation...
And, yes, you need to have preconverged WAVECAR
SYSTEM = yyyyyyyyyyy
ISTART = 1
ICHARG = 2
EDIFF = 1.0E-8
EDIFFG = -0.01
PREC = Accurate
NELM = 5
LVTOT= .FALSE.
ISMEAR = 0 ; SIGMA = 0.05
ENCUT= 520
NSW = 0 ! No relaxatioin.
...
...
...
LHFCALC = .TRUE.
HFSCREEN = 0.2
Time = .4
ALGO = D
GGA = PE
PRECFOCK = Normal
@ Pradeep R. Varadwaj: I appreciate for your updates: I have the following KPOINTS for HSE06 calculation of Band structure for Silicon which i copied from vasp wiki. The first part is from IBZKPT file which is clear, but how do we calculate KPOINT path for the second part which we give zero weight. If our system is hexagonal, and tetragonal how do we set these second part of KPOINTS.
Automatically generated mesh
26
Reciprocal lattice
0.00000000000000 0.00000000000000 0.00000000000000 1
0.16666666666667 0.00000000000000 0.00000000000000 8
0.33333333333333 0.00000000000000 0.00000000000000 8
0.50000000000000 0.00000000000000 0.00000000000000 4
0.16666666666667 0.16666666666667 0.00000000000000 6
0.33333333333333 0.16666666666667 0.00000000000000 24
0.50000000000000 0.16666666666667 0.00000000000000 24
-0.33333333333333 0.16666666666667 0.00000000000000 24
-0.16666666666667 0.16666666666667 0.00000000000000 12
0.33333333333333 0.33333333333333 0.00000000000000 6
0.50000000000000 0.33333333333333 0.00000000000000 24
-0.33333333333333 0.33333333333333 0.00000000000000 12
0.50000000000000 0.50000000000000 0.00000000000000 3
0.50000000000000 0.33333333333333 0.16666666666667 24
-0.33333333333333 0.33333333333333 0.16666666666667 24
-0.33333333333333 0.50000000000000 0.16666666666667 12
0.00000000 0.00000000 0.00000000 0.000
0.00000000 0.05555556 0.05555556 0.000
0.00000000 0.11111111 0.11111111 0.000
0.00000000 0.16666667 0.16666667 0.000
0.00000000 0.22222222 0.22222222 0.000
0.00000000 0.27777778 0.27777778 0.000
0.00000000 0.33333333 0.33333333 0.000
0.00000000 0.38888889 0.38888889 0.000
0.00000000 0.44444444 0.44444444 0.000
0.00000000 0.50000000 0.50000000 0.000
I mean to ask how to generate suitably modified KPOINTS for Band Structure using HSE functional ??
You can use XCRYSDEN to generate desired KPOINTS by using k-path option. Ofcourse you should convert your POSCAR to .xsf format first , then you can open it by xcrysden and proceed.
Dinesh Thapa You could find the second part of the K-point file for hybrid band structure from Vaspkit. Use your POSCAR file as a input and generate hybrid basis set K-points. Otherwise you could generate from following site https://www.materialscloud.org/work/tools/seekpath
Radhakrishnan Anbarasan ,Sir, I did scf with normal KPOINT mesh
INCAR tags
LHFCALC = .TRUE.
HFSCREEN = 0.2
Time = 0.4
ISYM = 0
and generated IBZKPT file which I copied to HSE_kpoints file for Bandstructure also I added kpoints generated by vaspkit and copied the CHGCAR from previous scf run.then I run another scf with new kpoints. The question is when I run vaspkit to generate bandstructure it gives error as line mode is not there in kpoints file.
Shall I copy IBZKPT under the kpoints generated by vaspkit.
Hybrid functional band structures require one to start from a preconverged WAVECAR using PBE-GGA functionals and a modified IBZKPT file. Once you've finished the PBE-GGA relaxation calculation, copy the INCAR, IBZKPT, POTCAR, CONTCAR and WAVECAR into a new folder, rename the IBZKPT to KPOINTS and CONTCAR to POSCAR. Then, I usually look up a few band structures of either my material (if they exist) or a similar structure and follow their k-path of high symmetry. These points are added as 0 weighted points at the end of the IBZKPT file, making sure to add the number of points added to the total number of points at the top of the file. Then, run using NSW = 0 (I'd also reduce TIME to 0.2. HSE06 does not support using a CHGCAR with a normal band structure KPOINTS file, so you will need to start from the WAVECAR from the previous run. Plotting can be done either using p4vasp or pymatgen (although I am having issues with pymatgen plotting the hybrid band structure). Hope this helps some. This site details many of the points in different 1st BZs ...you'll need to search for your structure/crystal (http://lampx.tugraz.at/~hadley/ss1/bzones/sc.php).
Can someone help me with the plotting part after the calculations are done? I am using p4vasp but the I do not know how to mark the high-symmetry points.
I would highly suggest looking at sumo-plot …it is much easier to work with when looking at hybrid functional band structures …if you prefer p4vasp you have to remove all of the eigenvalues from the non-zero weight kpoints from your Vasprun.XML file or you can just zoom into the region on the far right of the plot to see the region of interest (usually the far right of the plot)
I have zoomed into the right region of the plot in p4vasp but I need the mark the high symmetry points. Where di I get the distances between k-points?
To be honest I am not a big fan of p4vasp because I use Macs and have never been able to get it to work (I’ve used it on windows PCs though) …in reading on vasp forums it seems that you can’t add labels in p4vasp …i strongly suggest trying out sumo plot …it is a command line tool that makes nice plots: https://smtg-ucl.github.io/sumo/sumo-bandplot.html …if you do decide to use sumo and have questions feel free to ask them here
Absolutely!! Feel free to ask about any issues as there are some tricky things …I can happily share any inputs you might need so you can see an example. Best of luck!!
Thanks Eric for the help. Will get back to you in case I get stuck somewhere :)
Hi Eric! I tried sumo-bandplot for HSE band structure but even here the high-symmetry points aren't marked.
You have to add the labels in your kpoints file at the end of the line that represents that high symmetry point (at gamma you must use \Gamna) before running sumo plot
Do I use this format of KPOINTS?
k-points for bandstructure L-G-X-W
100 ! 100 line intersection
Line-mode
reciprocal
0.5 0.5 0.5 !L
0.00000 0.00000 0.00000 !G
0.00000 0.00000 0.00000 !G
0.5 0 0.5 !X
0.5 0 0.5 !X
0.5000000000 0.2500000000 0.7500000000. !W
Or the one I use for fake scf run?
Sorry just saw your response from yesterday …yeah you have to use the fake weight one with labels …glad you got it!! Sumo plot is nice because you can spilt the spin up and down channel projections as well as plot a DOS structure beside the band structure …don’t hesitate to ask any further questions
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