Research data for "Device-scale atomistic modelling of phase-change memory materials"

This is a dataset related to the publication "Device-scale atomistic modelling of phase-change memory materials".

Two folders have been provided for (1) the production data shown in this work, and (2) GAP models trained in this work:

(1) The production data have been categorised according to the main text figures:

• "reference_database":  Reference databases (i.e., training structures) of three GAP models discussed in this work. The structure data are provided in (extended) XYZ format, as labelled using either the PBEsol or the PBE functional.
  • "main_GST-GAP-22_PBEsol": the main GST-GAP-22 database, which was fitted using a two-step iterative training protocol. The resulting GAP model was used to obtain the results shown in the main text. The reference database is visualised in Fig. 1 of the main text. 
  • "refitted_GST-GAP-22_PBE": this dataset contains the same structures as the original GST-GAP-22 training data, with all structures having been relabelled using the PBE functional.
  • "extended_GST-GAP-22_for_efield_PBEsol": an extension of the GST-GAP-22 database to a new, task-specific application, i.e., electromigration under an external electric field (cf. Extended Data Fig. 4).

• "crystallization_simulations": three trajectories for the crystallization simulations shown in Fig. 2, of which all were obtained from GAP-MD.
  • "fig2b_growth_GAP-MD": Growth of Ge₁Sb₂Te₄ (1008 atoms).
  • "fig2c_cumulative_set_cycles_GAP-MD": Cumulative set process of Ge₁Sb₂Te₄ (1008 atoms).
  • "fig2d_crystallization_12096at_GAP-MD": Crystallization of Ge₁Sb₂Te₄ (12096 atoms), in which three crystalline seeds were used.

• "RESET_mushroom_model": two non-isothermal simulations shown in Fig. 3, obtained from GAP-MD.
  • "Fig3b_small_pulse": The 70 ps NVE equilibrium process after a small heating pulse was imposed in the focal area, giving an excess kinetic energy of 1,650 eV for the atoms in the focal area.
  • "Fig3d_large_pulse": The 70 ps NVE equilibrium process after a large heating pulse was imposed in the focal area, giving an excess kinetic energy of 3,900 eV for the atoms in the focal area.

• "RESET_device_scale_simulations": the GAP-MD simulations of the melting and heat dissipation process of a device-scale structural model shown in Fig. 4.
  • "Fig4b_device_scale_heating_10ps": The melting process of the device-scale model over 10 ps.
  • "Fig4c_device_scale_cooling_40ps": The heat dissipation process of the device-scale model over another 40 ps.

(2) The GAP models trained in this work:

• "main_GAP_potential": the main GAP model used for the production data of this work, which is fitted based on PBEsol data. The XML identifier of this GAP model is GAP_2022_4_7_480_18_6_12_970.

• "other_GAP_potentials": two derivatives of the original GAP model.
  • "refitted_GST-GAP-22_PBE": using the same reference structures as the original GAP model but re-labelled using the PBE functional. The XML identifier of this GAP model is GAP_2022_5_7_480_0_58_2_26.
  • "extended_GST-GAP-22_for_efield_PBEsol": An extension of the original GAP model to a new, task-specific application, i.e., electromigration under an external electric field. The XML identifier of this GAP model is GAP_2023_3_19_480_18_14_10_174.