Requests for technical support from the VASP group should be posted in the VASP-forum.


From Vaspwiki
Jump to navigation Jump to search

IVDW = 0 | 1 | 10 | 11 | 12 | 2 | 20 | 21 | 202 | 4
Default: IVDW = 0 

Description: This tag controls whether vdW corrections are calculated or not. If they are calculated IVDW controls how they are calculated.

Popular local and semilocal density functionals are unable to describe correctly van der Waals interactions resulting from dynamical correlations between fluctuating charge distributions. A pragmatic method to work around this problem is to add a correction to the conventional Kohn-Sham DFT energy :

The correction term is computed using some of the available approximate methods. The choice of vdW method is controlled via the following tags:

All methods listed above add vdW correction to potential energy, interatomic forces, as well as stress tensor and hence simulations such as atomic and lattice relaxations, molecular dynamics, and vibrational analysis (via finite differences) can be performed. Note, however, that these correction schemes are currently not available for calculations based on density functional perturbation theory.

N.B.: The parameter LVDW used in previous versions of VASP (5.2.11 and later) to activate DFT-D2 method is now obsolete. If LVDW=.TRUE. is defined, IVDW is automatically set to 1 (unless IVDW is specified in INCAR).

Related Tags and Sections

LVDW, DFT-D2, DFT-D3, Tkatchenko-Scheffler method, Tkatchenko-Scheffler method with iterative Hirshfeld partitioning, Many-body dispersion energy, dDsC dispersion correction

see also the alternative vdW-DF functionals: LUSE_VDW, VdW-DF functional of Langreth and Lundqvist et al.

Examples that use this tag