Hi dear all
I am doing *atomic relaxation* of a system containing 7 atoms in the
primitive unit cell (conventional unit cell contains 21 atoms)
1) i got the max. force tolerance < 0.0002 eV/Ang, but stress components
seems to be large as follows:
Stress-tensor-Voigt (kbar): -5.09 16.77 19.82
-12.79 -3.98 -8.53
Here i set "variable cell" option " false ".
What should be the max tolerance of the stress components?
2) if i take supecell =unit cell, even then SIESTA takes an internal
auxiliary supercell, here 6x6x5=180 atoms with non zero kgrid cutoff.
Although with zero value of kgrid
cutoff, it doesn't take internal auxiliary supercell. how does it
happen? Is it because of periodic boundary condition? but boundary
condtion in SIESTA is not mentioned
in the manual.
can anybody help me?
With Kind Regards,
1009U
