For the Fe6 site, the electrostatic environment is markedly different. Regardless of the protonation state of His195, the electric field strengths around this site tend to be small: except for a handful of evaluation points, the field strength never exceeds +0.4 VÅ -1 . In stark contrast to Fe2, the distance attenuation is relatively pronounced: as one approaches the Fe6 site, the size of the quivers decreases much faster than for the Fe2 site. Furthermore, in the regions on the outer evaluation spheres around Fe6 where the OLEF tend to be become significant, it uniformly points in the opposite direction than what is observed for Fe2, i.e., the field is directed towards the FeMoco. The relative radial isotropicity/consistency of the field surrounding Fe6 indicates that, here as well, the direction of the electric field direction is not caused by a single dominating residue but is the combined result of several residues surrounding the site.