The ABINIT Users Mailing List ( CLOSED )

[Thierry Deutsch <tdeutsch@cea.fr>]

Hi,

        I would like to calculate the Si surface with ABINIT using geometry 
optimization. The goal is not to have an accurate result but to test for a 
new development.

I have tried to tune some parameters  tsmear (0, 1000K and 5000K). but ABINIT 
does not converge in the SCF cycle.

diemac is 12 maybe an higher value is better.

Maybe someone has already calculated the Si(100) with ABINIT ?

Thierry Deutsch# Definition de la cellule
acell 7.6791796436859 7.6791796436859 30.716 angstrom

# Maximum number of step (DEFAULT=1)
nstep 1000

timopt -2

# Definition des types d''atomes
ntype 1           # deux types
zatnum 14   # silicium

# Definition de l'energie de coupure (en HARTREE)
ecut  7.5

# Definition geometrique
natom 64               # 64 atomes par maille
type 1 1 1 1 1 1 1 1   # tous de type 1 : Si 
     1 1 1 1 1 1 1 1
     1 1 1 1 1 1 1 1
     1 1 1 1 1 1 1 1
     1 1 1 1 1 1 1 1
     1 1 1 1 1 1 1 1
     1 1 1 1 1 1 1 1
     1 1 1 1 1 1 1 1

xangst  #Coordonnées cartésienne en angström
  6.069e+00  9.598e-01  1.068e+00
  6.069e+00  4.799e+00  8.087e-01
  3.529e+00  9.598e-01  5.487e-01
  3.529e+00  4.799e+00  2.887e-01
  6.719e+00  9.598e-01  6.108e+00
  6.719e+00  4.799e+00  6.108e+00
  2.879e+00  9.598e-01  6.108e+00
  2.879e+00  4.799e+00  6.108e+00
  6.719e+00  9.598e-01  1.153e+01
  6.719e+00  4.799e+00  1.153e+01
  2.879e+00  9.598e-01  1.153e+01
  2.879e+00  4.799e+00  1.153e+01
  6.719e+00  9.598e-01  1.696e+01
  6.719e+00  4.799e+00  1.696e+01
  2.879e+00  9.598e-01  1.696e+01
  2.879e+00  4.799e+00  1.696e+01
  4.799e+00  2.879e+00  3.393e+00
  4.799e+00  6.719e+00  3.393e+00
  9.598e-01  2.879e+00  3.393e+00
  9.598e-01  6.719e+00  3.393e+00
  4.799e+00  2.879e+00  8.823e+00
  4.799e+00  6.719e+00  8.823e+00
  9.598e-01  2.879e+00  8.823e+00
  9.598e-01  6.719e+00  8.823e+00
  4.799e+00  2.879e+00  1.425e+01
  4.799e+00  6.719e+00  1.425e+01
  9.598e-01  2.879e+00  1.425e+01
  9.598e-01  6.719e+00  1.425e+01
  4.799e+00  2.879e+00  1.968e+01
  4.799e+00  6.719e+00  1.968e+01
  9.598e-01  2.879e+00  1.968e+01
  9.598e-01  6.719e+00  1.968e+01
  6.719e+00  2.879e+00  2.036e+00
  6.719e+00  6.719e+00  2.036e+00
  2.879e+00  2.879e+00  2.036e+00
  2.879e+00  6.719e+00  2.036e+00
  6.719e+00  2.879e+00  7.466e+00
  6.719e+00  6.719e+00  7.466e+00
  2.879e+00  2.879e+00  7.466e+00
  2.879e+00  6.719e+00  7.466e+00
  6.719e+00  2.879e+00  1.289e+01
  6.719e+00  6.719e+00  1.289e+01
  2.879e+00  2.879e+00  1.289e+01
  2.879e+00  6.719e+00  1.289e+01
  6.719e+00  2.879e+00  1.832e+01
  6.719e+00  6.719e+00  1.832e+01
  2.879e+00  2.879e+00  1.832e+01
  2.879e+00  6.719e+00  1.832e+01
  4.799e+00  9.598e-01  4.751e+00
  4.799e+00  4.799e+00  4.751e+00
  9.598e-01  9.598e-01  4.751e+00
  9.598e-01  4.799e+00  4.751e+00
  4.799e+00  9.598e-01  1.018e+01
  4.799e+00  4.799e+00  1.018e+01
  9.598e-01  9.598e-01  1.018e+01
  9.598e-01  4.799e+00  1.018e+01
  4.799e+00  9.598e-01  1.561e+01
  4.799e+00  4.799e+00  1.561e+01
  9.598e-01  9.598e-01  1.561e+01
  9.598e-01  4.799e+00  1.561e+01
  5.449e+00  9.598e-01  2.091e+01
  5.449e+00  4.799e+00  2.065e+01
  3.098e-01  9.598e-01  2.143e+01
  3.098e-01  4.799e+00  2.117e+01


# Definition des parametres d'iteration
toldfe 1.0e-9     # stop sur difference d'energie
diemac 12.0       # constante dielectrique du Si massif pour l'initialisation

# No optimization of the cell
optcell 0
# Optimization of the atomic positions (bfgs)
ionmov 2

#Fermi-Dirac smearing (finite-temperature metal) 
occopt 3
#Gives the broadening of occupation numbers
tsmear 5000 K
iscf 5

#TOLerance on the MaXimal Force
tolmxf 2.57e-6
#Maximum number of Broyden step
ntime 1000

nband 200