# Crystalline AlAs : computation of the second derivative of the total energy
#
#Response-function calculation, with q=0
rfphon 1 # Will consider phonon-type perturbation
rfatpol 1 1 # Only the first atom is displaced
rfdir 1 0 0 # Along the first reduced coordinate axis
nqpt 1 # One wavevector is to be considered
qpt 0 0 0 # This wavevector is q=0 (Gamma)
kptopt 2 # Automatic generation of k points, taking
# into account the time-reversal symmetry only
tolvrs 1.0d-8 # SCF stopping criterion
irdwfk 1 # Read the ground-state wavefunctions
#######################################################################
#Common input variables
#Definition of the unit cell
acell 3*10.61 # This is equivalent to 10.61 10.61 10.61
rprim 0.0 0.5 0.5 # In tutorials 1 and 2, these primitive vectors
0.5 0.0 0.5 # (to be scaled by acell) were 1 0 0 0 1 0 0 0 1
0.5 0.5 0.0 # that is, the default.
#Definition of the atom types
ntypat 2 # There are two types of atom
znucl 13 33 # 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, type 1 is the Aluminum,
# type 2 is the Arsenic.
#Definition of the atoms
natom 2 # There are two atoms
typat 1 2 # The first is of type 1 (Al), the second is of type 2 (As).
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 REDUCED coordinate of atom 1.
0.25 0.25 0.25 # Triplet giving the REDUCED coordinate of atom 2.
#Gives the number of band, explicitely (do not take the default)
nband 4 # For an insulator (if described correctly as an insulator
# by DFT), there is no need to include conduction bands
# in response-function calculations
#Exchange-correlation functional
ixc 1 # LDA Teter Pade parametrization
#Definition of the planewave basis set
ecut 3.0 # Maximal kinetic energy cut-off, in Hartree
#Definition of the k-point grid
kptrlatt -4 4 4 # In cartesian coordinates, this grid is simple cubic, and
4 -4 4 # actually corresponds to the so-called 8x8x8 Monkhorst-Pack grid.
4 4 -4 # It might as well be obtained through the use of
# ngkpt, nshiftk and shiftk .
#Definition of the SCF procedure
nstep 15 # Maximal number of SCF cycles
diemac 9.0 # 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.
# The dielectric constant of AlAs is smaller that the one of Si (=12).
## After modifying the following section, one might need to regenerate the pickle database with runtests.py -r
#%%
#%% [setup]
#%% executable = abinit
#%% test_chain = trf1_1.in, trf1_2.in, trf1_3.in, trf1_4.in
#%% input_prefix = trf1_1o
#%% [files]
#%% files_to_test =
#%% trf1_3.out, tolnlines= 2, tolabs= 1.100e-08, tolrel= 2.000e-4
#%% psp_files = 13al.981214.fhi, 33as.pspnc
#%% [paral_info]
#%% max_nprocs = 2
#%% [extra_info]
#%% authors = X. Gonze
#%% keywords = NC, DFPT
#%% description = Crystalline AlAs : computation of the second derivative of the total energy
#%%