The problem here is, there are two kinds of Osmium atoms. For the first and the third Osmiun atom, The Eighteen Electron Rule is not obeyed, but the second Osmium atom is different and is filled with 18 electrons.
Os(1&3) = 8e- 4 x COT = 8e- Os-Os = 1e- 17e- |
Os(2) =
8e- 4 x COT = 8e- 2 x Os-Os = 2e- 18e- |