Structure of the data

• VASP training data generation. The training data for the MTPs is generated in these active learning runs.

  • PE
    • NPT ensemble, 15 - 500 K (split into segments 15 K – 30 K, 30 K - 150 K, 150 K - 300 K, 300 K - 400 K and 400 K - 500 K)
    • NVT ensemble (fixed at 300 K cell), 15 K - 100 K
  • PT
    • NPT ensemble, 15 - 500 K
    • NVT ensemble (fixed at 300 K cell), 15 K - 100 K

• Moment Tensor Potential (MTP) training runs. Typically 5 training runs with different random initialisations are performed, which are labelled with a, b, c, d and e.

  • PE, MTP_MD
    • a, b, c, d ("best"), e
  • PE, MTP_phonon, NPT ensemble training data
    • a, b, c, d ("best"), e
  • PE, MTP_phonon, NVT ensemble training data
    • a, b, c ("best"), d, e
  • PT, MTP_MD
    • a, b, c ("best"), d, e
  • PT, MTP_phonon, NPT ensemble training data
    • a, b ("best"), c, d, e
  • PT, MTP_phonon, NVT ensemble training data
    • a, b, c, d, e

• VASP validation runs. VASP active learning runs are performed at 300 K in an NPT ensemble to determine RMSD_MD

  • PE
  • PT

• ALD-BTE calculations. collision matrices for each grid point are omitted due to their huge size.

  • PE (full BTE, 4×6×160 q-mesh)
    • DFT, 300 K cell
    • DFT, DFT-relaxed cell
    • MTP, 300 K cell
    • MTP, DFT-relaxed cell
  • PT (full BTE, 4×6×48 q-mesh)
    • MTP, 300 K unit cell
    • MTP, DFT unit cell

• MD-BTE calculations. The file with the velocities (named velocities_dyn.dump) requires up to 300 GB; therefore it is omitted. The renormalized force constants require 5 GB of storage (for PT) and are thus also omitted. The calculation is performed in two steps, employing first LAMMPS, and then Dynaphopy.

  • PE (simulation time of 1 ns, resolution of power spectrum 0.004 THz)
  • PT (simulation time of 2 ns, resolution of power spectrum 0.002 THz)

• AEMD simulations

  • PE
    • 432, 720, 1080, 1440, and 2160 cell repetitions
  • PT
    • 128, 192, 256, 384, and 512 cell repetitions

• NEMD simulations

  • PE
    • 216, 288, 432, 576, 720, 1080, and 1440 cell repetitions
  • PT
    • 128, 256, 512, and 1024 cell repetitions

A Note on axis relabelling

In order to align the polymer chains along the z-direction, and to be consistent with our previous publication "Designing Accurate Moment Tensor Potentials for Phonon-Related Properties of Crystalline Polymers" (https://www.mdpi.com/1420-3049/29/16/3724), we relabeld the axis in the following way:

PE

x --> z

y --> y

z --> x

PT

x --> y

y --> x

z --> z

Example

The q-mesh for the phono3py calculation of PE is given as 160×15×10 in the job-submission-script where phono3py is called, but in the paper (and above) it is written as 10×15×160. All calculations (including POSCAR files etc.) are consistent with each other in terms of their axis labels. Just for the paper, the axis relabelling was performed.