# I can't figure out crystal planes with negative intercepts

As seen above, I don't follow how you figure out those planes. It seems they're not using the origin labeled. I'm not really sure I understand spatially what's going on in the left figure so let's focus only on the right figure. Why is one of the intercepts not really touching the xyz axes? Where is the origin in this thing?

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You may be aware of this already but I believe these are Miller Indices - are you familiar with those? –  Mark Rovetta May 1 at 21:10
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## 1 Answer

The notation in the figures looks correct to me for the planes shown if you interpret the numbers in parentheses as representing Miller Indices. Miller indices form a notation system in crystallography for planes in crystal (Bravais) lattices.

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