Radius ratio

[asdf1]

in the radius ratio of a crystal, what is the difference between the radius of the interstitial atom and large atom?

 

[HallsofIvy]

Don't you think that depends one heckuva lot on exactly what crystal you are talking about and what the atoms are?

Unless you are asking about the difference in meaning and I would think that would be obvious!

 

[asdf1]

i guess so, but i saw that in a textbook about crystallography, and i'm not really clear on what's the difference... it'd be nice if that book could show those two things in a picture or diagram...

 

[lightgrav]

The bulk of a crystal is a repeating pattern,
so a "unit cell" can be centered on any atom.
There are many different types of "unit cells",
some retained for the sake of tradition.

Whenever the book describes structure vectors,
assemble a set of sticks in 3-d to show them.
Especially at first, 2-d drawings might not cut it.

 

[asdf1]

ok, thanks!