Recent free-electron laser (X-FEL) studies have suggested S-3 states with many features as expected based on previous model calculations and spectroscopy. However, in one of them there is one dramatic surprise. An hydroxide (at the O6 position) on Mn1 was expected, but this group is missing in that X-FEL structure. It has previously been concluded that the hydroxide, which fills the sixth position of the octahedral coordination of Mn1, is necessary to oxidize this manganese to form the S-3 state. In the present study, S-3 structures without the O6 hydroxide have been investigated. Finally, also some S-2 structures were studied. (C) 2017 Published by Elsevier B.V.