# Calculating lattice thermal conductivity using Quantum ESPRESSO and phonopy

How should I calculate lattice thermal conductivity in Quantum ESPRESSO? I have installed phonopy. My Linux distribution is Ubuntu.

• I'm kind of new to this, but from what I've read you might need to use the ShengBTE code along with QE in order to find the lattice thermal conductivity. Jul 19, 2021 at 19:25
• @AnoopANair yes. That’s what I will be trying to solve this. If I get it done successfully, I will post the steps here after as answer to this problem. Jul 20, 2021 at 5:19
• @epsilon02fft Did you have any luck? Aug 24, 2021 at 0:47
• @NikeDattani Yes I did. I was successful in performing phonopy and phono3py calculations for Si. The codes ran successfully, but I am facing further problems of mpirun and RAM limitations about which I will post soon. Apologies for not responding before, couldn’t login to my account and also got busy with uni official work. Nov 21, 2021 at 10:23

• First, you need to create a QE input file (pwscf), using ibrav=0, lattice vectors in bohr units, atomic coordinates in crystal units.
• Using the input file, run phono3py/third_order.py to create supercell within finite displacement method.
• Then you need to write a script that will copy all header option, specially &control and &system to each supercell file and rename to scf.in and generate sequential folder namely, disp-00001..., ect.
• Now run pwscf for each supercell and please do not forget to select force calculation in pwscf input file.
• After this step you need to run phono3py to calculate second order (harmonic) and third order (anharmonic) force constants.
• Finally, run phono3py to calculate lattice thermal conductivity using dense q-point grid and primitive cell.