[Solved] Convert FCC to SC
Posted: Thu Jan 31, 2013 4:56 pm
Hello!
At the moment I'm trying to convert tutorial #3 from the fcc coordinates to sc coordinates because I need the wavefunction in the whole cubic cell.
To do this, I started from the file tbase3_5.in by substituting the basis vectors with the simple cubic ones and replacing the k-vectors with their coordinates in cartesian space.
The next step was the replacement of
and finally the correction of the atom's positions.
After adding the option because the symmetry finder complained about not finding a primitive lattice, I got an unphysical bandstructure.
For example at Gamma, there is the lowest band, then a 6 times degenerate band followed by another 6 times degenerate band (when you also increase the number of bands).
Could anyone explain, what I am doing wrong? Any help is appreciated.
Thanks!
Sunny
At the moment I'm trying to convert tutorial #3 from the fcc coordinates to sc coordinates because I need the wavefunction in the whole cubic cell.
To do this, I started from the file tbase3_5.in by substituting the basis vectors with the simple cubic ones and replacing the k-vectors with their coordinates in cartesian space.
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rprim 1.0 0.0 0.0
0.0 1.0 0.0
0.0 0.0 1.0
kptbounds2 0.25 0.25 0.25 # L point
0.0 0.0 0.0 # Gamma point
0.0 0.0 0.5 # X pointThe next step was the replacement of
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nshiftk1 1
shiftk 1 0.5 0.5 0.5and finally the correction of the atom's positions.
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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 # Triplet giving the REDUCED coordinate of atom 1.
1/4 1/4 1/4 # Triplet giving the REDUCED coordinate of atom 2.
2/4 2/4 0.0
3/4 3/4 1/4
2/4 0.0 2/4
3/4 1/4 3/4
0.0 2/4 2/4
1/4 3/4 3/4After adding the option
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chkprim 0For example at Gamma, there is the lowest band, then a 6 times degenerate band followed by another 6 times degenerate band (when you also increase the number of bands).
Could anyone explain, what I am doing wrong? Any help is appreciated.
Thanks!
Sunny