(Experimental) This variable selects which van der Waals
correction to apply to the correlation functional.
Options:
none:
No correction is applied.
vdw_ts:
The scheme of Tkatchenko and Scheffler, Phys. Rev. Lett. 102
073005 (2009).
vdw_d2:
DFT-D2 corrections, equivalent to specifying version = 2 in the DFTD3 library.
vdw_d3_zero_damping:
DFT-D3 corrections, damping the dispersion contribution to zero for short ranges.
This is equivalent to specifying version = 3 in the DFTD3 library.
For more details, see [J. Chem. Phys. 132, 154104 (2010)](https://doi.org/10.1063/1.3382344).
vdw_d3_bj:
DFT-D3 with Becke-Johnson finite-damping, variant 2. In Octopus 15.0 and older, this was only option with the DFT-D3 library, and was
specified with "vdw_d3".
This is equivalent to specifying version = 4 in the DFTD3 library.
For more details, see [Effect of the damping function in dispersion corrected density functional theory](https://doi.org/10.1002/jcc.21759).
vdw_d3m_zero_damping:
DFT-D3 corrections, damping the dispersion contribution to zero for short ranges. This uses the modified damping function and parameters
of Sherrill and coworkers. For more details see [J. Phys. Chem. Lett. 2016, 7, 12, 2197–2203](https://doi.org/10.1021/acs.jpclett.6b00780)
This is equivalent to specifying version = 5 in the DFTD3 library.
vdw_d3m_bj:
DFT-D3 with Becke-Johnson finite-damping, and the modified parameters of Sherrill and coworkers.
For more details see [J. Phys. Chem. Lett. 2016, 7, 12, 2197–2203](https://doi.org/10.1021/acs.jpclett.6b00780)
This is equivalent to specifying version = 6 in the DFTD3 library.