Hi,

Here is the CONTROL file of ShengBTE.

*********************

&allocations

nelements=2,

natoms=2,

ngrid(:)=12 12 12

&end

&crystal

lfactor=0.5715017844,

lattvec(:,1)=0.0 0.5 0.5,

lattvec(:,2)=0.5 0.0 0.5,

lattvec(:,3)=0.5 0.5 0.0,

elements="Ga" "As"

types=1 2,

positions(:,1)=0.00 0.00 0.00,

positions(:,2)=0.25 0.25 0.25

scell(:)=5 5 5

&end

¶meters

T=300

scalebroad=1.0

&end

&flags

espresso=.true.

nonanalytic=.true.

isotopes=.true.

&end

*************

I have some questions regarding the file. Would you please explain me the questions below?

q1) Does scell means a supercell size? For example: scell(:)= 5 5 5 means that 5*5*5 supercell?

q2) If scell means 5*5*5 supercell here, would I have to run pw.x considering 5*5*5 supercell to generate 2nd_order force constant by Quantum Espresso?

q3) How about 3rd order force constant using thirdorder_espresso.py? Should we use same supercell (5*5*5)?

Thank you