Figure 45.

GPR models provide a unified view into structural and electronic properties of complex systems—here exemplified for dense disordered silicon, simulated using a system containing 100,000 atoms. The upper panels show atomic structures, obtained from a GAP-driven molecular-dynamics simulation in which an a-Si sample was compressed from ambient pressure to 20 GPa. The simulation revealed a series of structural transitions, from a low-density amorphous (LDA)/high-density amorphous (HDA) phase persisting up to about 11 GPa, through a distinct very-high-density amorphous (VHDA) phase with much higher coordination numbers at about 13 GPa, to the eventual formation of a polycrystalline structure with simple hexagonal grains. The lower panels show the corresponding electronic structures as described by the machine-learned densities of states (ML-DOS), which were also obtained in a GPR framework. Adapted from ref (164), where more details may be found.