Restarting finite displacement calculations for large super cells

[saranya_velliyarat]

Hello,

I am working on a system with 15 atoms in the unit cell and I want to calculate both phonon dispersion and conductivity using SERTA. For the phonon dispersion, I am computing force constants using a 2x2x2 supercell (120 atoms). For the 45 degrees of freedom in the 2×2×2 supercell, the finite-difference method requires 2 displacements per degree of freedom, resulting in a total of 90 displacements, which makes the calculation computationally expensive. Similarly, for the conductivity calculation using SERTA, the first step is to compute the electron-phonon potentials on the same 2×2×2 supercell. Since this also relies on the finite difference method, it takes a significant amount of time and computational resources.

My question is: Is there a reliable way to restart these calculations in VASP if they time out, without losing the already computed displacements or electron-phonon potentials?

Any advice would be greatly appreciated.

Thank you!

[alex]

Hi there,

unfortunately, there is not, neither for finite differences nor DFPT. So either it fits into your time limit or you need to think differently.
One hint may be to use an external driver software, e.g. phonopy, to split your job into smaller pieces. However, I don't know if this example does that job.

Cheers,

alex