Hi all, I am running some calculations for a bilayer material (NiI2), and using
vdw_xc 7
to treat the van der Waals interactions. I’m using the PBE functional and PAW datasets.
I noticed in my calculations that abinit prints ******** for the max and min C6:
====> STARTING DFT-D3 computation
Begin the computation of the Coordination Numbers (CN)
required for DFT-D3 energy corrections…
… Done.
max(CN) = 5.69899 (atom 3) ; min(CN) = 4.79827 (atom 6)
Begin the computation of the C6(CN)
required for DFT-D3 energy corrections…
… Done.
max(C6) =******** ; min(C6) =********
Begin the computation of pair-wise term
of DFT-D3 energy contribution…
…Done.
Van der Waals DFT-D3 semi-empirical dispersion potential with Becke-Jonhson (BJ) refined by Grimme et al. J. Comput. Chem. 32, 1456 (2011)
Scaling factors: s6 = 1.000, s8 = 0.787 Damping parameters: a1 = 0.429, a2 = 4.441 Cut-off radius = 1.23713E+02 Bohr Number of pairs contributing = 98064 DFT-D3 (no 3-body) energy contribution = -7.04279E-02 Ha
I checked previous calculations of a different material which used vdw_xc 7, and this didn’t occur. But in both cases the DFT-D3 energy contribution has the same order of magnitude, and the calculations here finish without any errors or warnings.
Has anyone come across this before? I’m wondering if I should be worried about this, and if so how I can fix it.
Thanks,
Daniel Bennett