I have a rhombohedral structure

enter image description here

The SYSTEM and CELL_PARAMETERS blocks looks like this:

  ibrav = 0
  A =  6.058435171
   0.494845678   0.494845678   0.000000000
   0.494845678  -0.000000000   0.494845678
   0.000000000   0.494845678   0.494845678

What's the right value of ibrav that I should use and what are the changes that I should make in my input file to save the same structure? I also already checked https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm224 but I couldn't find it

  • $\begingroup$ You set the ibrav value for the original cell. In this case it is FCC, so ibrav would be equal to 2. $\endgroup$ Apr 10 at 12:25
  • $\begingroup$ Congratulations on reaching 1000! $\endgroup$ Apr 10 at 12:27
  • $\begingroup$ @HemanthHaridas if I have to set the ibrav of conventional cell which is 2 I have to use the lattice parameter of conventional cell, which I don't know yet. I want to use xcrysden to find the lattice parameter of conventional cell that's why I wanted ibrav of primitive cell $\endgroup$
    – Camilla
    Apr 10 at 12:41
  • 2
    $\begingroup$ @NikeDattani Thank you so much. I'm happy to belong to such amazing community :D $\endgroup$
    – Camilla
    Apr 10 at 12:42
  • 1
    $\begingroup$ @Camilla there are not two different type of input files for primitive and conventional cells. You simply set ibrav=2. The scaling factor 0.5 is already implemented inside ibrav=2. So no need to worry about the specific cell_parameters you got here. $\endgroup$ Apr 10 at 12:55


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