LPMO Cu sites in LsAA9_A(f), LsAA9_A(Ec) and TaAA9_A at the lowest and highest X-ray doses. LsAA9_A(f) at (a) low and (b) high dose. LsAA9_A (Ec) at (c) low and (d) high dose. TaAA9_A at (e) low and (f) high dose. The distances between Cu (orange spheres) and the equatorial/axial water molecules (red spheres) increase with increasing X-ray dose in the transition from Cu2+ to Cu+. In some cases, the water molecules have been modelled in a double conformation (b) or left unmodelled due to a lack of electron density (d). Distances below 2.2/2.7 Å are shown as full lines (coordination distance), below 2.9/3.2 Å as dashed lines (close to coordination distance) and above 2.9/3.2 Å with no line (not coordinating) for the equatorial/axial ligands, respectively. 2Fo–Fc electron density is shown at a 1.0 contour level as blue mesh.