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[ccp4bb]: Re: Heavy atom sites



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> 1        0.3164  0.0508  0.1172     16.87    2.71   23.38      3.44       1
> 2        0.1836  0.4492  0.1172      9.79   23.95   23.38      3.44       1
> 3        0.8164  0.5508  0.1172     43.53   29.37   23.38      3.44       1
> 4        0.6836  0.9492  0.1172     36.45   50.61   23.38      3.44       1
> 5        0.8242  0.4453  0.1191     43.94   23.74   23.77      2.48       2
> 6        0.1758  0.5547  0.1191      9.37   29.57   23.77      2.48       2
> 7        0.6758  0.0547  0.1191     36.03    2.92   23.77      2.48       2
> 8        0.3242  0.9453  0.1191     17.29   50.40   23.77      2.48       2
> 9        0.6289  0.6289  0.0098     33.53   33.53    1.95      2.34       3
>
The first four are related by symmetry

# 1 is x, y, z
# 2 is 1/2 - x, 1/2 - y, z
# 3 is 1/2 + x, 1/2 + y, z
# 4 is 1 - x, 1-y, z so it's really -x, -y, z

The next are really close to  symmetry with the first (probably NCS close
to a symmetry element):
#5 is ~ 1/2 + x, 1/2 - y, z
#6 is ~ 1/2 - x, 1/2 + y, z
#7 is ~ -x, y, z
#8 is ~ x, -y, z

now for P 43 21 2, the symmetry operators are (thanks Bernhard!):
X,     Y,     Z
 1/2 -Y,1/2 +X,3/4 +Z
-X,    -Y,1/2 +Z
 1/2 +Y,1/2 -X,1/4 +Z
Y,     X,    -Z
 1/2 +X,1/2 -Y,1/4 -Z
-Y,    -X,1/2 -Z
 1/2 -X,1/2 +Y,3/4 -Z

and for P 41 21 2
 X,     Y,     Z
 1/2 -Y,1/2 +X,1/4 +Z
 -X,    -Y,1/2 +Z
 1/2 +Y,1/2 -X,3/4 +Z
Y,     X,    -Z
 1/2 +X,1/2 -Y,3/4 -Z
-Y,    -X,1/2 -Z
 1/2 -X,1/2 +Y,1/4 -Z

None of your heavy atom sites are related by a 41 screw (z + 1/4, etc), and
there is no fourfold rotation (x and y would be related). Look through the
IT and see what space group corresponds to the symmetry you do have.

Hope this helps,

Lisa

--
Lisa Edberg (205)934-1611 FAX:(205)934-0480
UAB Center for Biophysical Sciences/Engineering
http://www.cmc.uab.edu/misc/edberg/index.html
"It's not always that Nature is being nasty to us.
Sometimes also we are stupid." -Thomas Schneider