The ABINIT Users Mailing List ( CLOSED )

[Jedo <jedokim@umich.edu>]

Hi all,

I am trying to compare if I get the same result for primitive cells and 
conventional cell when performing the electronic band structure 
calculation. I may be totally wrong because I am just starting the 
calculation. I am using two different structures, one for conventional 
cell and one for primitive cell. Shouldn't the following structure give 
me the same results? Not sure why I'm getting a totally different band 
structures.  Please let me know if I'm just stupid.  :)    Thanks!!

Primitive cell

#Definition of the unit cell
-> acell 3*10.217         # This is equivalent to   10.217 10.217 10.217
-> rprim  0.0  0.5  0.5   # FCC primitive vectors (to be scaled by acell)
->        0.5  0.0  0.5
->        0.5  0.5  0.0
->
-> #Definition of the atom types
-> ntypat 1          # There is only one type of atom
-> znucl 14          # The keyword "znucl" refers to the atomic number of the
->                   # possible type(s) of atom. The pseudopotential(s)
->                   # mentioned in the "files" file must correspond
->                   # to the type(s) of atom. Here, the only type is
-> Silicon.
->
->
-> #Definition of the atoms
-> natom 2           # There are two atoms
-> typat 1 1         # They both are of type 1, that is, Silicon.
-> xred              # This keyword indicate that the location of the atoms
->                   # will follow, one triplet of number for each atom
->    0.0  0.0  0.0  # Triplet giving the REDUCED coordinate of atom 1.
->    1/4  1/4  1/4  # Triplet giving the REDUCED coordinate of atom 2.




Conventional Cell

#Definition of the unit cell
acell 3*10.217          # This is equivalent to   10.18 10.18 10.18
rprim  1.0  0.0  0.0   # FCC primitive vectors (to be scaled by acell)
         0.0  1.0  0.0  
         0.0  0.0  1.0

#Definition of the atom types
ntypat 1          # There is only one type of atom
znucl 14          # The keyword "znucl" refers to the atomic number of the
                 # possible type(s) of atom. The pseudopotential(s)
                 # mentioned in the "files" file must correspond
                 # to the type(s) of atom. Here, the only type is Silicon.
                       

#Definition of the atoms
natom 8           # There are two atoms
typat 1 1 1 1 1 1 1 1       # They both are of type 1, that is, Silicon.
xred              # This keyword indicate that the location of the atoms
                 # will follow, one triplet of number for each atom  
  0.0  0.0  0.0
  1/4  1/4  1/4
  1/2  1/2  0.0
  0.0  1/2  1/2
  1/2  0.0  1/2
  3/4  3/4  1/4
  1/4  3/4  3/4
  3/4  1/2  3/4


--
================================
Jedo Kim, 
Heat Transfer Physics Laboratory
2350 Hayward, 2186 GG Brown Bldg.
University of Michigan, Ann Arbor, MI 48109-2143
Email: jedokim@umich.edu, jdzbox@hotmail.com
Tel: 734-764-3487 (o);  734-276-8370 (cell)
================================