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?

• Well, the overall shape of the molecule doesn't get anything close to bent and/or tetrahedral. I suggest doing some readings about hybridization and MO basics, rather than sticking to most-beloved, most-loathed VSEPR. – M.A.R. Apr 25 '15 at 13:15
• I am going to start reading about hybridization after Vespr – Simon-Nail-It Apr 25 '15 at 13:23
• @MARamezani The VSEPR model should be digested in a very careful way - it predicts some molecular shapes correctly for the entirely wrong reasons. And for those reasons it is also often very wrong. – Martin - マーチン Apr 25 '15 at 17:38

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