Dichromate ion: Tetrahedral or bent? I am currently studying about the vespr theory and I'm stuck on an ion which is dichromate (VI) ion $\ce{Cr2O7^2-}$. So this is what I am thinking about:

1) If I make the oxygen atom at the middle the centre atom, it is a bent.
2) If I make the chromium atom thecentre atom, it is a tetrahedral.

So, my problem is that whether dichromate (VI) ion bent or tetrahedral?
Both, Bent about Oxygen and tetrahedral about chromium:

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