[Pw_forum] the high symmetry line of bcc phonon dispersion calculated by pw4.1.2

[Wei Zhou]

first let me  thank Ngoc Linh Nguyen for your reply.
      the high  symmetry *H-P-Gam-H-N-P-N-Gam is found in other papers,
which is correct. what I feel puzzled is the coordination of high symmetry
points.
      from the web of
http://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-kv-list, it give the
crystal coordination of bcc as following ;
k-vector label Wyckoff position  Parameters
CDML  ITA  ITA
GM  0,0,0  4
H  1/2,-1/2,1/2
P  1/4,1/4,1/4
N  0,0,1/2  24
and the pwscf give the following bcc basis
 reciprocal axes: (cart. coord. in units 2 pi/a_0)
                b(1) = (  1.000000  0.000000  1.000000 )
                b(2) = ( -1.000000  1.000000  0.000000 )
                b(3) = (  0.000000 -1.000000  1.000000 )
then I changed the above coordination H, P,N, into 2pi unit, they became
 Gam(0,0,0) ,H( 1.00  -1.00,1.00), P(0.00,0.00, 0.50),N(0.00, -0.50, 0.50),
when I plot the phonon dispersion using the above coordination in 2pi unit,
I found the results is wrong . I just to feel puzzle why my results is wrong


 The correct coordination shoud be G :(0,0,0) ,H( 0.00  1.00,0.00),
P(0.5,0.5, 0.50),N(0.5, 0.5, 0.00), so it is strange for me to this results



-- 
ZhouDawei
JiLin Universiyt ,ChangChun ,China
zdw2000 at gmail.com
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