Fig. 2: Spatial correlations of the unit-cell dipoles computed on a 5 × 5 × 5 supercell simulated at 250 K.
From: Thermodynamics and dielectric response of BaTiO3 by data-driven modeling
a Slice at constant Z of the correlation of the X-component of the dipole of the unit-cell centered on one Ti-atom (circled in red) with the X-component of the dipole of every other Ti-centered cell. b 3D view of the dipole correlations for the lower half of the same 5 × 5 × 5 supercell; the full 3 × 3 correlation tensor of each dipole with the central Ti-atom (red sphere) is shown as an ellipsoid, where the elongation along the Cartesian axes shows the presence of highly directional, needle-like correlations91.
