Statistical density modification with non‐crystallographic symmetry

Statistical density modification is a technique for phase improvement through a calculation of the posterior probability of the phases, given experimental phase information and expectations about features of the electron‐density map. The technique can take advantage of both estimates of electron density in the map and uncertainties or probability distributions for those estimates. For crystals with non‐crystallographic symmetry (NCS), this allows the use of the expected similarity of electron density at NCS‐related points without requiring an implicit assumption that these regions are identical.