Re: [Ifeffit] non-standard space group P 21/n

Dear Andrea, To convert the atomic positions, use the following equations (starred positions are in the P21/c setting) a* = c b* = b c* = a+b To convert the unit cell, A* = C B* = B C* = sqrt{[Ccos(90-beta)]^2+[A-Csin(90-beta)]^2} beta* = 90 - cos-1[Ccos(90-beta)/C*] where cos-1 is the inverse cosine function If you have problems, please double check my geometry for converting the unit cell parameters. Sincerely, Wayne On Fri, Dec 5, 2014 at 9:04 AM, wrote:

Dear Gordon,

thank you for your reply. I tried to use the space group P1, but the resulting local structure around the absorber atoms is completely different from that expected.

Andrea

HI Andrea,

My suggestion, if you know where all the atoms are in the unit cell, is to use

space group P1. It may be tedious and brute force in nature, but you won't have to worry about origin choices or non-standard space groups. You will still know

which atoms are equivalent and can pick an appropriate one as your target atom.

regards, Robert

On Fri, Dec 5, 2014 at 8:07 AM, Sanson Andrea wrote:

Dear all

does anyone know if is it possible to create with ATOMS the non-standard space group P 21/n ?

Space group keywords are listed at the atoms website http://iffwww.iff.kfa-juelich.de/icp/atoms/atoms.sgml-7.html#ss7.4 but no keyword for P 21/n group is available.

Thanks for any suggestion. Best regards, AS

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