[Pw_forum] Issue regarding reciprocal path in band calculation

[Éric Germaneau]

Dear all,

After a SCF calculation of a crystal with the following cell parameters

  * ibrav = 14,
    celldm(1)=5.913520,celldm(2)=1.386316,celldm(3)=1.593551,
    celldm(4)=0.084426,celldm(5)=0.313644,celldm(6)=0.268903

I performed a band calculation (restart_mode='from_scratch') using the 
path bellow which has been generated by xcrysden.

      K_POINTS crystal
               40
             0.5000000000    0.0000000000    0.0000000000    1.0
             0.4500000000    0.0000000000    0.0000000000    1.0
             0.4000000000    0.0000000000    0.0000000000    1.0
             0.3500000000    0.0000000000    0.0000000000    1.0
             0.3000000000    0.0000000000    0.0000000000    1.0
             0.2500000000    0.0000000000    0.0000000000    1.0
             0.2000000000    0.0000000000    0.0000000000    1.0
             0.1500000000    0.0000000000    0.0000000000    1.0
             0.1000000000    0.0000000000    0.0000000000    1.0
             0.0500000000    0.0000000000    0.0000000000    1.0
             0.0000000000    0.0000000000    0.0000000000    1.0
             0.0000000000    0.0714285714    0.0000000000    1.0
             0.0000000000    0.1428571429    0.0000000000    1.0
             .....

But in the output the path looks like this :

          number of k points=    40
                            cart. coord. in units 2pi/alat
             k(    1) = (   0.5000000  -0.1395931  -0.1651425), wk =  
    0.0500000
             k(    2) = (   0.4500000  -0.1256338  -0.1486282), wk =  
    0.0500000
             k(    3) = (   0.4000000  -0.1116745  -0.1321140), wk =  
    0.0500000
             k(    4) = (   0.3500000  -0.0977152  -0.1155997), wk =  
    0.0500000
             k(    5) = (   0.3000000  -0.0837559  -0.0990855), wk =  
    0.0500000
             k(    6) = (   0.2500000  -0.0697965  -0.0825712), wk =  
    0.0500000
             k(    7) = (   0.2000000  -0.0558372  -0.0660570), wk =  
    0.0500000
             k(    8) = (   0.1500000  -0.0418779  -0.0495427), wk =  
    0.0500000
             k(    9) = (   0.1000000  -0.0279186  -0.0330285), wk =  
    0.0500000
             k(   10) = (   0.0500000  -0.0139593  -0.0165142), wk =  
    0.0500000
             k(   11) = (   0.0000000   0.0000000   0.0000000), wk =  
    0.0500000
             k(   12) = (   0.0000000   0.0534944  -0.0000050), wk =  
    0.0500000
             k(   13) = (   0.0000000   0.1069887  -0.0000101), wk =  
    0.0500000
             .....

and like this

               k = 0.5000-0.1396-0.1651     band energies (ev):
               k = 0.4500-0.1256-0.1486     band energies (ev):
               k = 0.4000-0.1117-0.1321     band energies (ev):
               k = 0.3500-0.0977-0.1156     band energies (ev):


I compared the lattice and reciprocal lattice parameter in both the scf 
and band outputs, and they are (obviously) exactly same.
So I'm just wondering what's going on here.
What did I do wrong?

Thank you,

                                                 Éric.

-- 
/Be the change you wish to see in the world
/ --- Mahatma Gandhi ---

Dr. Éric Germaneau 
<http://www.linkedin.com/pub/%C3%A9ric-germaneau/30/931/986>

Graduate University of Chinese Academy of Sciences
College of Physical Sciences
Yuquan Road 19A
Beijing 100049
China

/Please, if possible, don't send me MS Word or PowerPoint attachments
Why? See: http://www.gnu.org/philosophy/no-word-attachments.html/

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