ABINIT Discussion Forums

Dear all
where i can find tests on Abinit that calculate elastic properties and thermodynamic properties of a compound ???

Kind regards

Read and do the tutorials on the response functions, there are several there that do what you want.

Dear jzwanzig,

I want to caclulate the bulk module for a cubic zinc Blende crystal structure of the binary compound CdS by method of increasing the "acell", i tried firstly through the toturespon (elastic toturial 6) and i got alot of warnings, actually i don't know how to calcuate it so please can you explain for me how i do that step by step and in below is my input file :


Best regards...



ndtset 12 # Total number of datasets (3*4)
udtset 3 4 # Double loop for k-sample convergence study

nspden 2
nsppol 2
nspinor 1

# Set 1 : Initial self-consistent and lattice optimization run

getwfk?1 0
ionmov?1 2 # Broyden lattice optimization scheme
ntime?1 5 # Maximim lattice optimization steps
optcell?1 1 # Optimize cell volume only
strfact?1 100 # Test convergence of stresses (Hartree/bohr^3) by
# multiplying by this factor and applying force
# convergence test
tolmxf?1 1.0e-6 # Convergence limit for forces as above
tolvrs?1 1.0d-18 # Need excellent convergence of GS quantities for RF runs

# Set 2 : Additional iteration to print density just at converged acell

prtden?2 1 # Third dataset needs density
tolvrs?2 1.0d-18

# Set 3 : Converge unoccupied wave functions

getden?3 -1 # Use density from previout set
tolwfr?3 5.0d-19 # Only wave function convergence can be used with
# non-self-consistent calculation
tolwfr23 1.0d-30 # This is simply for a reason of portability of automatic tests
nstep23 25 # This is simply for a reason of portability of automatic tests
nstep33 35 # This is simply for a reason of portability of automatic tests

# Set 4 : response-function calculations for all needed perturbations

kptopt?4 2 # Time-reversal only for RF calculation
nqpt?4 1
qpt?4 0 0 0 # By symmetry, only need one direction
rfdir?4 1 0 0
rfstrs?4 3 # Need both unaxial and shear strains
tolvrs?4 1.0d-12 # Need reasonable convergence of 1st-order quantities

#Common input data

#Double loop data passing

getcell -1 # Start from optimized (datasets ?2-?4) or previously
# optimized (datasets ?1) acell
getwfk -1 # Use last set of wave functions (except datasets ?1)


#Lattice definition
acell 3*10.96 # Starting value
dilatmx 1.05 # Allow for optimization
rprim 0.0 0.5 0.5
0.5 0.0 0.5
0.5 0.5 0.0

#Definition of the atom types and atoms
ntypat 2
znucl 48 16
natom 2
typat 1 2

#Atomic position
xred 0.0 0.0 0.0
0.25 0.25 0.25

#Definition of the plane wave basis set
ecut 20.947118 # Maximum kinetic energy cutoff (Hartree)
ecutsm 0.5 # Smoothing energy needed for lattice parameter
# optimization. This will be retained for
# consistency throughout.

#Definition of the k-point grid - loop over 3 k-point densities

ngkpt1? 6 6 6
ngkpt2? 8 8 8
ngkpt3? 10 10 10

nshiftk 4 # Use one copy of grid only (default)
shiftk 0.0 0.0 0.5 # This gives the usual fcc Monkhorst-Pack grid
0.0 0.5 0.0
0.5 0.0 0.0
0.5 0.5 0.5

#Definition of occupation numbers and number of bands
nband 10 # With metallic occup
occopt 4 # Femi-function smearing
tsmear 0.02

#Definition of the self-consistency procedure
iscf 5 # Use conjugate-gradient SCF cycle (datasets 1 & 3)
nstep 50 # Maximum number of SCF iterations
# This might not be enough for the very demanding tolwfr?3 above,
# but was chosen for portability reasons.
# enforce calculation of forces at each SCF step
optforces 1


#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test =
#%% telast_6.out, tolnlines= 0, tolabs= 0.000e+00, tolrel= 0.000e+00, fld_options = -medium
#%% psp_files = 13al.pspnc, 33as.pspnc
#%% [paral_info]
#%% max_nprocs = 1
#%% [extra_info]
#%% author =
#%% keywords =
#%% description =
#%%<END TEST_INFO>

Hi forume,

i am trying to caculate elastic constant for a compound i got this warnings:
hdr_check: WARNING -
band,k 5, input occ= 2.0000000E+00 disk occ= 1.9999972E+00

hdr_check: WARNING -
band,k 6, input occ= 2.0000000E+00 disk occ= 1.9999208E+00

hdr_check: WARNING -
band,k 7, input occ= 2.0000000E+00 disk occ= 1.9990895E+00
here is my input file :

ndtset 12 # Total number of datasets (3*4)
udtset 3 4 # Double loop for k-sample convergence study

# Set 1 : Initial self-consistent and lattice optimization run

getwfk?1 0
ionmov?1 2 # Broyden lattice optimization scheme
ntime?1 25 # Maximim lattice optimization steps
optcell?1 1 # Optimize cell volume only
strfact?1 100 # Test convergence of stresses (Hartree/bohr^3) by
# multiplying by this factor and applying force
# convergence test
tolmxf?1 1.0e-6 # Convergence limit for forces as above
tolvrs?1 1.0d-18 # Need excellent convergence of GS quantities for RF runs

# Set 2 : Additional iteration to print density just at converged acell

prtden?2 1 # Third dataset needs density
tolvrs?2 1.0d-18

# Set 3 : Converge unoccupied wave functions

getden?3 -1 # Use density from previout set
tolwfr?3 5.0d-19 # Only wave function convergence can be used with
# non-self-consistent calculation
tolwfr23 1.0d-30 # This is simply for a reason of portability of automatic tests
nstep23 10 # This is simply for a reason of portability of automatic tests
nstep33 20 # This is simply for a reason of portability of automatic tests

# Set 4 : response-function calculations for all needed perturbations

kptopt?4 2 # Time-reversal only for RF calculation
nqpt?4 1
qpt?4 0 0 0 # By symmetry, only need one direction
rfdir?4 1 0 0
rfstrs?4 3 # Need both unaxial and shear strains
tolvrs?4 1.0d-12 # Need reasonable convergence of 1st-order quantities

#Common input data

#Double loop data passing

getcell -1 # Start from optimized (datasets ?2-?4) or previously
# optimized (datasets ?1) acell
getwfk -1 # Use last set of wave functions (except datasets ?1)


#Lattice definition
acell 3*10.9604 # Starting value
dilatmx 1.6 # Allow for optimization
rprim 0.0 0.5 0.5
0.5 0.0 0.5
0.5 0.5 0.0
strprecon 0.6

#Definition of the atom types and atoms
ntypat 2
znucl 48 16
natom 2
typat 1 2

#Atomic position
xred 0.0 0.0 0.0
0.25 0.25 0.25

#Definition of the plane wave basis set
ecut 20.94 # Maximum kinetic energy cutoff (Hartree)
ecutsm 0.5 # Smoothing energy needed for lattice parameter
# optimization. This will be retained for
# consistency throughout.

#Definition of the k-point grid - loop over 3 k-point densities

ngkpt1? 6 6 6
ngkpt2? 8 8 8
ngkpt3? 10 10 10

nshiftk 4 # Use one copy of grid only (default)
shiftk 0.0 0.0 0.5 # This gives the usual fcc Monkhorst-Pack grid
0.0 0.5 0.0
0.5 0.0 0.0
0.5 0.5 0.5

#Definition of occupation numbers and number of bands
nband 12 # With metallic occup
occopt 3 # Femi-function smearing
tsmear 0.02

#Definition of the self-consistency procedure
iscf 7 # Use conjugate-gradient SCF cycle (datasets 1 & 3)
nstep 99 # Maximum number of SCF iterations
# This might not be enough for the very demanding #tolwfr?3 above
# but was chosen for portability reasons.
# enforce calculation of forces at each SCF step
optforces 1