Hello Everyone,
I am a very beginner to Quantum Espresso. I create input file using Cif2QE (Qetoolkit) for 2H MoS2 monolayer supercell (221).
First, I have done ‘scf’ calculation to converge the ecutwfc (from 20 to 100) from that i fix 60 as final ecutwfc. Similarly i have done K points convergence from that i fix 4 4 1 as final K points.
Secondly, I am doing ‘vc-relax’ for the above final ecutwfc and K points. Still i did’t get output its running for past one day.
My question: Is this correct way to proceed calculation.
My input file not open in XcrysDen. Its shows error message.Why?
I attached my input files and output files. Please Kindly help me to proceed my calculation in a correct way
You are following right steps.
For vc-relaxation you need to fix lattice vector along z-axis. Because if you look at your cell volume during the relaxation the z-vector shrinks and x, y lattice vectors expand during the relaxation. You have isolated your system by adding vacuum along z-axis, then you need to relax lattice vector along z-axis.
you may use
cell_dofree = 'xy',
in &CELL section
Thankyou Naseem Sir, I will follow your suggestion and i will add output after finishing calculation. Please kindly verify. Thanks a lot Sir.
Hello Sir,
I have done the calculation using the cell_dofree='xy' command in the input file but its shows error as Error in routine checkallsym (2): not orthogonal operation.
you can turnoff the symmetry by using
nosym = .true.,
in section &SYSTEM
I am running with this option and it is running fine. I will share the output once it is done. In the meanwhile you can try this option.
Thankyou Naseem Sir, Thankyou very much for given output. Sir, i used cell_dofree='2Dxy' in input file and the i get output. I attached the files. Sir, Whether its correct or not to use '2Dxy' for this calculation of monolayer 221 MoS2
You can relax the primitive cell parameters using "2Dxy"
Use the relaxed cell parameters and atom positions to make a 221 cell.
You don't need to do the relaxation of cell parameters again,
means you don't use calculation = 'vc-relax' for 221 cell.
You may want to relax the 221 structure by just relaxing the atom positions
use
calculation = 'relax'
Naseem Sir, I have done relax calculation and after that i have done scf calculation and then band structure calculation using pwgui to fix k-points. Sir, Please verify the files
Naseem Sir, How to decide and give number in "Total number of k-points along the path" in XCrysden in k path selection. Sir, I messaged Bulk 2H MoS2
Naseem Sir, Whats the role of ecutrho, I increased 4 times compare to ecutwfc, is it enough .
For 'smearing' - Which one is correct to use in MoS2 (Fermi dirac or gaussian)
Sir, I messaged about supercell .
Thanks in Advance
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