The ABINIT Users Mailing List ( CLOSED )

[taoj0003@ntu.edu.sg]

Hi,
I m a new user of ABINIT. I want to calculate the TiO2 rutile structure as 
beginning. I dont know much about those parameters, anyone can give me an 
suggestion or example? I tried to do so by change some parameter from 
Tutorial t35. Any one can help me check whether my change is ok or not. 
thanks 



# Crystalline TiO2 
#
# Computation of the band structure.
# First, a SCF density computation, then a non-SCF band structure calculation.


ndtset 2
prteig 1
#Dataset 1 : usual self-consistent calculation
kptopt1 1          # Option for the automatic generation of k points,
                   # taking into account the symmetry
chkprim  0  
prtden1  1         # Print the density, for use by dataset 2

toldfe1  1.0d-6

#the band structure
iscf2    -2
getden2  -1
kptopt2  -3
nband2   8

ndivk2   10 12 17      # 10, 12 and 17 divisions of the 3 segments, delimited
                       # by 4 points.
kptbounds2  0.5  0.0  0.0 # L point
            0.0  0.0  0.0 # Gamma point
            0.0  0.5  0.5 # X point
            1.0  1.0  1.0 # Gamma point in another cell.
tolwfr2  1.0d-12
enunit2  1             # Will output the eigenenergies in eV 


#Definition of the unit cell
acell 4.59  4.95 2.96 angstrom  

#Definition of the atom types
ntypat 2          # There is only one type of atom
znucl 22  8       # 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 6           # There are two atoms
typat 1 1 2 2 2 2 # 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 cartesian coordinates of atom 1, 
   0.5   0.5   0.5    # Triplet giving the cartesian coordinates of atom 2
   0.305 0.305 0.0    # Triplet giving the cartesian coordinates of atom 3
   0.695 0.695 0.0    # Triplet giving the cartesian coordinates of atom 4
   0.195 0.195 0.5    # Triplet giving the cartesian coordinates of atom 5
   0.805 0.805 0.5    # Triplet giving the cartesian coordinates of atom 6


#Definition of the planewave basis set
ecut 1.0         # Maximal kinetic energy cut-off, in Hartree

#Definition of the SCF procedure
nstep 10          # Maximal number of SCF cycles
diemac 12.0       # Although this is not mandatory, it is worth to
                  # precondition the SCF cycle. The model dielectric
                  # function used as the standard preconditioner
                  # is described in the "dielng" input variable section.