[Pw_forum] Questions on display Fermi Surface(continued)

[张 洪彬]

>On Tue, 2005-05-31 at 09:45 +0000, Paolo Giannozzi wrote:
> > On Tuesday 31 May 2005 02:34, �洪彬 wrote:
> >
> > > I have been wondering how to get a 3D/2D fermi surface after
> > > my calculation of band structure, but I don't know how to do.
> >
> > have a look at XcrySDen: http://www.xcrysden.org/
>
>In particular, you might look at:
>
>http://www.xcrysden.org/doc/XSF.html
>
>where you should read the following sections:  Specification of 2D and
>3D scalar-fields and Bandgrids (visualization of Fermi surfaces)
>
>Regards, Tone
Thank you for you kind guide first.
  
   After reading the XSF.html mentioned, It seems to me it's easy to get a 
Fermi surface of a realistic material plotted. However when I try to follow 
the example of the given Fermi surface along with XCrysDen package, which 
is said to be that of RhFCCBulk, and try to get a similiar picture through 
my own calculation on FCC structured Rh metal, I found it's so hard. Thus 
here I want to ask 2 further questions:
    1. In the sample Fermi Surface file, when define "first spanning vector 
of the bandgrid (i.e. first reciprocal lattice vector)" and the two 
follows, the data are different from the PWSCF format I think, as to the 
first reciprocal lattice vector, say, in the example file it gives 
C(i+j-k), where C is a constant; but in the PWSCF format, the first 
reciprocal lattice vector should be D(-i-j+k) format, and further more,the 
two constants C, D don't have the same value or a value I can interprete in 
an reasonable way. And, the fermi energy given isn't the same as what I 
calculated. So, what's wrong? Is the sample Fermi Surface XSF file belong 
to element Rh with FCC structure?
    2. I wonder if there is a convenient way to get energy values which 
should be inputted in the XSF Fermi Surface file. You see, in the XSF file, 
one must get energy for a K-grid in the whole reciprocal unit cell, while 
calculation performed by PWSCF usually in the Brillouin Zone. Do I have to 
get it manually one by one for those K_points beyond the first Brillouin 
Zone?
 
With my kindest Regards

Hongbin Zhang

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