ABINIT Discussion Forums

The vdw test in abinit-8.6.1/tests/vdwxc/t03.in gives the results in abinit-8.6.1/tests/vdwxc/Refs/t03.out , but also the sa,e results if I remove all vdw lines in the input. So:

Unit cell
acell 3*10.0 angstrom
chkprim 0

# Atoms
ntypat 1
znucl 4
natom 2
typat 1 1

# Positions
xcart
-1.5 0.0 0.0
1.5 0.0 0.0

# Convergence
prtden 0
prteig 0
prtwf 0
ecut 15.0
nstep 50
toldfe 1.0d-6
ixc -102130


gives the same results as

Unit cell
acell 3*10.0 angstrom
chkprim 0

# Atoms
ntypat 1
znucl 4
natom 2
typat 1 1

# Positions
xcart
-1.5 0.0 0.0
1.5 0.0 0.0

# Convergence
prtden 0
prteig 0
prtwf 0
ecut 15.0
nstep 50
toldfe 1.0d-6
ixc -102130

# vdW-DF parameters
vdw_xc 1
vdw_df_zab -0.8491
dw_df_ndpts 10
vdw_df_dcut 5.0
vdw_df_dratio 10.0
vdw_df_dsoft 1.0
vdw_df_phisoft -1.0
vdw_df_nqpts 10
vdw_df_qcut 5.0
vdw_df_qratio 10.0
vdw_df_nrpts 128
vdw_df_rcut 10.0
vdw_df_rsoft 0.0
vdw_df_ngpts -1
vdw_df_gcut 5.0
vdw_df_acutmin 10.0
vdw_df_aratio 10.0
vdw_df_damax 1.0
vdw_df_damin 1.0e-2
vdw_df_nsmooth 3
vdw_df_threshold 1.0e-2
vdw_df_tolerance 1.0e-13
vdw_df_tweaks 0
irdvdw 1
prtvdw 1

both give:

ETOT 35 -22.758619402799 -3.303E-07 2.140E-10 7.348E-02

ETOT 35 -22.758619402799 -3.303E-07 2.140E-10 7.348E-02

It has been a few months and there has been no response. Someone must know the status of the vdw code in abinit? Thanks!
Ron

Dear recohen, vdW-DF functionals are not fully operational yet. In the new Abinit version there will be an error message when vdw_xc = 1,2. This will be so until the implementation is completed and debugged, hopefully in a couple of months. Sorry for the inconvenience.

Thank you very much! It has been some months. I do not see a mention in the 8.8.3 release notes. Could you please tell me the status? Thank you!

Ron