[Pw_forum] Doubt for plotting bandgap with ibrav=0

[Jane Fernandez]

Hello Quantum Espresso Users!

I installed QE on ubuntu and ran the first example for plotting band gap
for silicon structure successfully. Then I tried graphene structure using
the following:

&SYSTEM
 ibrav= 4, celldm(1)= 4.602, celldm(3) = 4, nat= 2, ntyp= 1,
....
ATOMIC_POSITIONS {alat}
C 0.00 0.00 0.00
C 0.00 0.57735026918962576451 0.00
K_POINTS {tpiba_b}
....
I got the correct results for bandgap of graphene.

Now if I want to run for free bravais lattice with ibrav=0 for supercells
consisting of 3 hex rings

&SYSTEM
  ibrav = 0 ,  A =    9.17901,  nat = 14,  ntyp = 1
/
CELL_PARAMETERS {alat}
  1.000000000000000   0.000000000000000   0.000000000000000
  0.000000000000000   1.000000000000000   0.000000000000000
  0.000000000000000   0.000000000000000   1.000000000000000
ATOMIC_SPECIES
   C   12.01060   C.pz-van_ak.UPF
ATOMIC_POSITIONS {alat}
C   0.200001000000000   0.827165000000000   0.500000000000000
C   0.366667000000000   0.807920000000000   0.500000000000000
C   0.433333000000000   0.653960000000000   0.500000000000000
C   0.100000000000000   0.692450000000000   0.500000000000000
C   0.166666666666667   0.538491000000000   0.500000000000000
C   0.600000000000000   0.634715000000000   0.500000000000000
C   0.666666666666667   0.480756000000000   0.500000000000000
C   0.333333333333333   0.519246000000000   0.500000000000000
C   0.400001000000000   0.365286000000000   0.500000000000000
C   0.833333333333333   0.461511000000000   0.500000000000000
C   0.900000000000000   0.307551000000000   0.500000000000000
C   0.566667000000000   0.346041000000000   0.500000000000000
C   0.633334000000000   0.192080000000000   0.500000000000000
C   0.800000000000000   0.172835000000000   0.500000000000000
K_POINTS {tpiba_b}
......

I do not obtain graphene band gap structure. I just get parallel bands. Can
anyone please help? I want to use ibrav=0 because I also want to run on
deformed structures on supercells in future.

Thanks in advance!

-Jane
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170727/858e42c0/attachment.html>