The tungsten atoms have two oxidation states in this lattice (W 6+ and W 5+ ) and three coordination types (Figure ). The most prevalent one is the octahedral [W 6+ O6] (black). Two tungsten atoms in oxidation state 6+ are in pentagonal bipyramidal conformation (brown). The third type of tungsten is in oxidation state 5+ and forms a W 5+ -W 5+ pair (marked in Figure as grey atoms and in Figure encircled by yellow oval line). From the symmetrical point of view, there are multiple types of oxygen atoms. Roughly speaking the oxygen atoms could be sorted into six groups to distinguish their contribution to the ELNES. The most abundant oxygen atoms are those bonded to tungsten 6+ (blue). The second most abundant oxygen atoms (orange) are "triple" bonded to tungsten 6+ (two of them are in octahedral arrangement and one in pentagonal bipyramidal arrangement). The next oxygen atoms (yellow) are "triple" linked to octahedral tungsten (6+); another octahedral tungsten (5+) and tungsten (6+) in pentagonal bipyramid arrangement. The red oxygen atoms are bonded to two tungsten 5+ and one 6+.