# No subject

Tue Sep 25 15:04:34 PDT 2012

```=A0 * =A0-k,-h,-l<br>
...<br>
<br>
I understand that going from P1 to C2, one needs to apply the transformatio=
n matrix (x-y, x+y,z) on the P1 cell to form the C2 cell, and (-k, -h, -l) =
on the reflections.<br>
<br>
Naive question: why aren&#39;t the two matrices similar?<br>
The reciprocal space is the fourier transform of the real space; i was thin=
king that a reorientation matrix in the real space would be kept in the rec=
iprocal space. My maths are not that good, and in P1 it is more complex tha=
n other space groups. Can someone tell me why the matrices are different?<b=
r>

<br>
Also, in C2 there is a 2-fold axis parallel to b, so reflections (h,k,l) ar=
e equivalent to (-h, k, -l).<br>
In P1, they are not. Applying the above transformation matrix on the reflec=
tions would give (hP1, kP1, lP1) transforms into (-kP1, -hP1, -lP1), and th=
ese are equivalent to (kP1, -hP1, lP1)? Is this correct?<br>
<br>
thank you<br>
vincent<br>
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arch Scientist<br>Berkeley Center for Structural Biology<br>Lawrence Berkel=
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