Dear all,
First of all, I'm a beginner for Quantum Espresso.
According to topic
'https://www.researchgate.net/post/How_to_make_Input_file_for_evx_means_for_energy_vs_volume_calculations_in_QUANTUM_ESPRESSO'
' https://www.researchgate.net/post/How_to_find_the_lattice_parameters_from_PwScf '
and ' http://www.iiserpune.ac.in/~smr2626/hands_on/week1/jun30/simple_calcs_qe_mastani.pdf '
they say about calculated energy vs lattice parameter or volume.
I'm not understand and required tutorials :
1. QE input file?
2. How to calculate 'scf ? nscf? bands? relax? ...
3. How to use ev.x ?
Best Regards
Meena Rittiruam
Hi Meena,
If you are interested in finding the optimum lattice parameter for your simulation cell, you should have a good guess of a value (from experimental data or similar materials for example). Then you scan the lattice parameter values around your guess value at a fixed interval (say 0.1 Angstrom) and you record the energy at each lattice parameter value. There is not need to relax the atoms here. By performing this type of calculation, you should get a parabola. The optimum lattice parameter will correspond to the x-value of the minimum of this parabola. The corresponding energy value (the y-coordinate) will give you the cohesion energy.
I hope this is helpful.
Dear Adib Samin
Thank you for answers.
I will try calculate and report you again.
Best Regards
Meena Rittiruam
Dear Adib Samin
I'm run Si with different lattice in scf. It work.
I'm thankful for your suggestion.
Best Regards
Meena Rittiruam
Dear
to calculate the equation of state (EOS) for a given system using quantum espresso there is two methods. the manual method which consist on many calculations of the considered unicell with differents voulmes. so, in this case we fix a value for the lattice parameter or the cell voulme and we run ionic relaxation to find the total energy of the system. by repeating this step many times for different values of the cell voule we can obtain E(V) or E(a).
the second method is the automatic method; in this case we can simply use the eV.x tool in the bin folder and do interactively the work
best regards
Dear Mohamed Ali Lahmer
Previously I attempt to use ev.x, but not succes.
Pleae let me that how to use eV.x tool (espresso/bin/ev.x).
Best Regards
Meena Rittiruam
Dear Meena
You really did it
but as I saw in the snap you attached, there are several script files
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