*** For details on how to be removed from this list visit the ***
*** CCP4 home page http://www.ccp4.ac.uk ***
Dear BR:
Thank you for your quick reply.
From my data and my experience I believe my refinement with high
symmetry space group is right.
The problem is that if I assume both structures are right, how I can
describe the atom site relationship in both structures in terms of
symmetry, such as removing inversion center , or mirror planes.
By the way, if I transfer my high symmetry space group (I4/mcm) to
lower symmetry space group (I-4c2, which is also a subgroup of
I4/mcm), I got the atom sites of A, B, and D at 4a, 16i, and 8h
sites, respectively, in stead of the one reported in the literature
(4d, 16i and 8e sites). Is this a problem or not?
I hope I am not confusing you.
Your help is highly appreciated!
Best Regards!
Bin Li
At 10:24 PM 8/2/2006, you wrote:
The first thing I would look at is the |E**2-1| number
in the intensity distributions.
This should indicate whether centrosymmetric or not.
0.736 for acentric and 0.968 for centric structures.
If this is not decisive in small molecules, suspicion
is in order, but w/o more stats it is hard to say.
BR
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bin
Li
Sent: Wednesday, August 02, 2006 7:47 PM
To: [email protected]
Subject: [ccp4bb]: Question about symmetry relationship
*** For details on how to be removed from this list visit the ***
*** CCP4 home page http://www.ccp4.ac.uk ***
Dear:
I have a question about symmetry relationship between two space groups.
In the literature, there is a compound AB4C2. It was refined with
I-4c2 space group and A, B, and C are at 4d, 16i and 8e sites, respectively.
I got a new compound AB4D2 which can be refined very well with high symmetry
space group, I4/mcm. In my compound A, B, and D are 4a, 16l, and 8h sites,
respectively. If I draw both structures, they look same, except some bond
distances change.
The high symmetry space group is central symmetry and the another one in
non-central symmetry, but both have very similar Wyck positions.
How do I figure out the symmetry relationship between these two structures?
Your help is highly appreciated!
Thank you for your time!
Best Regards!
Bin Li
Bin Li, Ph.D
Ames Lab., Iowa State University
Ames, IA, USA
