[Wien] problems in lapw3

[B. Yanchitsky]

oops,

sorry, but probably I was wrong here, Cu atoms have D4h (tetragonal) local symmetry, i.e.
for Cu atom at (1/2,1/2,0) k-points (1,0,0) and (0,0,1) are not equivalent.
The difference in magnitude of X-ray atomic factor just reflects this fact.

Regards,
Bogdan


B. Yanchitsky wrote:
> Second problem is that for some cubic structures atomic X-ray factors are
> different in magnitude for symmetry equvalent atoms. Below is simple example.
> The structure is L12, Cu3Au,
> Cu atoms (all equivalent) at (1/2,1/2,0) (0,1/2,1/2) (1/2,0,1/2)
> Au atom at (0,0,0)
> In *output3 we can see the following
> 
> Equiv.atom            1  at   0.500000000000000       0.500000000000000
>    0.000000000000000E+000
> 
>    0  0  0  0.0000  27.7707  27.7707  0.00000  0.00000  0.00000  0.00000  0.00000
>   -1  0  0  0.1320 -25.7150 -25.7203  0.00462  0.00004  0.00057  0.00000  0.00000
>                     ^^^^^^^^
> -----
>   Equiv.atom            2  at   0.000000000000000E+000  0.500000000000000
>    0.500000000000000
> 
>    0  0  0  0.0000  27.7707  27.7707  0.00000  0.00000  0.00000  0.00000  0.00000
>   -1  0  0  0.1320  25.7294  25.7203  0.00925 -0.00012  0.00000  0.00000  0.00000
>                     ^^^^^^^^
> i.e. the terms with lm=00 have equival values, but contributions from lm!=00 are different.
> I'm not sure, but might be this comes from the point
> that k-vector (-1,0,0) is transformed in local frame of the first atom into (1,0,0)
> but in local frame of the second atom into (0,0,1). As a result lists of spherical harmonics
> (array YL) for both atoms are different, but from another point of view this should not do matter.
> 
> Regards,
> 
> Bogdan Yanchitsky
> Institute of Magnetism
> Vernadsky Blvd., 36-b
> 03142  Kiev
> UKRAINE
> 
> Tel. (+380-44) 444 34 20
> Fax. (+380-44) 444 10 20
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