[Pw_forum] Scf calculation help

[naphtaly moro]

Dear Pandey,
A good place to start is for example a unitcell of 8 atom with ibrav=1.
ATOMIC_POSITIONS
Si  0.000  0.000  0.000
Si  0.500  0.500  0.000
Si  0.500  0.000  0.500
Si  0.000  0.500  0.500
Si  0.250  0.250  0.250
Si  0.750  0.750  0.250
Si  0.750  0.250  0.750
Si  0.250  0.750  0.750

The you can either use pen and paper to expand it to 2x2x2 supercell or if
you dont want to do that, you can just used other softwares like VESTA or
GDIS to make your self. I have never come acorss the same errors as you
have when doing calculations on the Si.  To use GDIS you need to save the
sttructure in Fractional coordinates.




Kind Regards
==============================================
OUMA, Cecil Naphtaly Moro
PhD. Student
Physics Department, University of Pretoria, South Africa
Private bag X20
Hatfield
Pretoria
0028
Office 5-61, NW-1 Building
Cell: +27 721385182
==============================================
"Clouds are not spheres, mountains are not cones, coastlines are not
circles,and bark is not smooth, nor does lightning travel in a straight
line." - Benoit Mandelbrot *

The more progress physical sciences make, the more they tend to enter the
domain of mathematics, which is a kind of centre to which they all
converge. We may even judge the degree of perfection to which a science has
arrived by the facility with which it may be submitted to calculation.
Quoted in E Mailly, **Eulogy on Quetelet 1874 *
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