# -------------------------------------------------------------------
# h-BN - Test of Van der Waals dispersion potential with Becke-
# Jonhson damping (DFT-D3(BJ)) on elastic constants
# Test on distorted hexagonal boron nitride (to get non-zero internal
# strains)
# DATASET 1: ground-state
# DATASET 2: computation of the elastic constants and internal strains 
# by DFPT
# --------------------------------------------------------------------

  ndtset  2
  ecut 5 # Must be increased for convergence purposes
  ecutsm 0.5
  dilatmx 1.05
  ixc 11
# DATASET 1: ground-state computation
  kptopt1   1             
  tolwfr1   1.0d-24
# DATASET 2: elastic constants and internal strains       
  rfphon2   1      
  rfatpol2   1 2          
   rfdir2   1 1 1         
    nqpt2   1
     qpt2   0.0 0.0 0.0  
  rfstrs2   3
  getwfk2   1            
  kptopt2   2            
  tolvrs2   1.0d-16

acell 4.7407935029E+00  4.7407935029E+00  6.408898878
angdeg 90 90 120

nband 6
nbdbuf 2
ntypat  2
znucl 5 7
natom 2
typat  1 2
xred
0.0 0.0  0.24
1/3 2/3 0.75

ngkpt   2 2 1 # Must be increased for convergence purpose
nshiftk 1
shiftk  0.0 0.0 0.5
diemac 12.0

#vdW DFT-D input variables
vdw_xc 7 # Activate DFT-D3(BJ)
vdw_tol 1d-8 # Tolerance on the pair-wise term (1d-12 is safer for convergence purposes)

 pp_dirpath "$ABI_PSPDIR"
 pseudos "B-q3, PseudosHGH_pwteter/7n.5.hgh"

#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test = 
#%%   t99.out, tolnlines = 8, tolabs = 1.001e-04, tolrel = 5.0e-04, fld_options = -easy
#%% [paral_info]
#%% max_nprocs = 1
#%% [extra_info]
#%% authors = B. VAN TROEYE
#%% keywords = DFPT, ELASTIC, VDW, DFT-D3(BJ)
#%% description = 
#%%   Computation of the elastic constants and internal strains for
#%%   distorded h-BN (to get non-zero internal strains)
#%%   vdW-DFT-D3 corrections with Becke-Jonhson damping (DFT-D3(BJ))
#%%   Only the pair-wise is computed (3-body term not implemented)
#%%   In this test the following properties are thus tested: contribution
#%%   to the energy and to the stress of DFT-D3(BJ) as well as 
#%%   the contribution to the elastic constants and internal strains
#%% topics = vdw
#%%<END TEST_INFO>