Fig. 1: Electron density of orbital subspaces selected via exchange truncation.
From: Simple Fermionic backflow states via a systematically improvable tensor decomposition

The K = 5 orbital subspace (red) is shown for a central atom in a 6 × 6 lattice of hydrogen atoms in a STO-6G basis at both compressed (1.0 Å) and extended (2.0 Å) geometries.