2a & 2b yield the same structure that has c'=c/2 so this is not case.
2c & 2d yield again the same structure which is hexagonal close-packed - Mg structure
type.
Check cell dimensions against know structure types.
Peter Zavalij
University Crystallographer
Institute for Materials Research
and Che
If there are only two atoms, try any of the followings:
position 2a: 0,0,0; 0,0,0.5
position 2b: 0,0,0.25; 0,0,0.75
position 2c: 1/3,2/3,1/4; 2/3,1/3,3/4
position 2d: 1/3,2/3,3/4; 2/3,1/3,1/4
Best
===
[EMAIL PROTECTED] on Wed, 03 Nov 2004 21:36:27 +0500 wrote: Dear Dr. Zhang
Do you know what structure type it is? If yes just take the same atomic position for
you compound as for the known one.
If not you have to find it.
Anyway... be careful with the space group symbol - It should be "P 63/m m c" not "P 6
3 /m m c". NO SPACE between 6 & 3.
Peter Zavalij
Dr. Peter Y.
Dear Dr. Zhang and Dr. Marc,
Thank you for your reply.
Now just for my interest can you tell me for a hexagonal crystal structure with two
atoms per unit cell and space group P 6 3/m m c ( space group number 194) what would
be atoms position to be inserted in GSAS.
With best regards,
Apu
/_/_/
Dear friends,
For ur question, I feel better to you details.
simply, I quoted the text from International Crystallographic Volume A for
you ref.
"An asymmetric unit of a space group is a (simply connected) smallest closed
part of space from which, by application of all symmetry operation(hopefull
Dear Apu,
your question is very clear: you have determined the space group symmetry
from the systematic absences of your powder diagram and then you would like
to know where are the atoms in the unit cell, isn't it? I.e. which orbits of
the space group are occupied. Answering this question has been
Dear All,
One thing is sufferring me a lot. I don't have much idea about space groups.
In case of giving positions of atoms in GSAS, so far I understand when I am giving the
space group information, I should not have to give the positions of all the atoms. It
is understood from the space group
