IVDW: Difference between revisions

Latest revision as of 14:08, 30 September 2024

IVDW = 0 | 1 | 10 | 11 | 12 | 13 | 14 | 2 | 20 | 21 | 202 | 263 | 3 | 4
Default: IVDW = 0 (no correction)

Description: IVDW specifies a vdW (dispersion) correction.

For fundamental reasons, the semilocal and hybrid exchange-correlation functionals are unable to describe properly vdW interactions resulting from dynamical correlations between fluctuating charge distributions (called London dispersion forces). An approximate way to work around this problem and to get more reliable results for vdW systems is to add a dispersion correction term, $E_{\mathrm{disp}}$ , to the conventional KS-DFT energy $E_{\rm tot}^{\mathrm{KS-DFT}}$ :

E_{\rm tot}^{\mathrm{KS-DFT-disp}} = E_{\rm tot}^{\mathrm{KS-DFT}} + E_{\mathrm{disp}}.

$E_{\mathrm{disp}}$ can be calculated using one of the available approximate methods listed below.

IVDW=0 : no dispersion correction (default)
IVDW=1|10 : DFT-D2 method of Grimme^[1] (available as of VASP.5.2.11)
IVDW=11 : DFT-D3 method of Grimme with zero-damping function^[2] (available as of VASP.5.3.4)
IVDW=12 : DFT-D3 method with Becke-Johnson damping function^[3] (available as of VASP.5.3.4)
IVDW=13 : DFT-D4 method^[4] (available as of VASP.6.2 as external package)
IVDW=14 : One of the methods available in the Library libMBD of many-body dispersion methods^[5]^[6]^[7] (available as of VASP.6.4.3 as external package)
IVDW=2|20 : Tkatchenko-Scheffler method^[8] (available as of VASP.5.3.3)
IVDW=21 : Tkatchenko-Scheffler method with iterative Hirshfeld partitioning^[9]^[10] (available as of VASP.5.3.5)
IVDW=202 : Many-body dispersion energy method (MBD@rSC)^[11]^[12] (available as of VASP.5.4.1)
IVDW=263 : Many-body dispersion energy with fractionally ionic model for polarizability method (MBD@rSC/FI)^[13]^[14] (available as of VASP.6.1.0)
IVDW=3 : DFT-ulg^[15] method (available as of VASP.5.3.5)
IVDW=4 : dDsC dispersion correction^[16]^[17] method (available as of VASP.5.4.1)

With all methods listed above, a dispersion correction is added to the total energy, potential, interatomic forces and stress tensor, such that 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.

Mind: The libMBD implementations (IVDW=14) of the Tkatchenko-Scheffler methods and their MBD extensions are much faster (analytical calculation of the forces) than the VASP implementations (numerical calculation of the forces). Therefore, it is strongly recommended to use the libMBD implementation if available.

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

@@ Line 1: / Line 1: @@
-{{TAGDEF|IVDW|0 {{!}} 1 {{!}} 10 {{!}} 11 {{!}} 12 {{!}} 2 {{!}} 20 {{!}} 21 {{!}} 202 {{!}} 4|0 ffff}}
+{{TAGDEF|IVDW|0 {{!}} 1 {{!}} 10 {{!}} 11 {{!}} 12 {{!}} 13 {{!}} 14 {{!}} 2 {{!}} 20 {{!}} 21 {{!}} 202 {{!}} 263 {{!}} 3 {{!}} 4|0 (no correction)}}
-Description: {{TAG|IVDW}} specifies a vdW correction.
+Description: {{TAG|IVDW}} specifies a vdW (dispersion) correction.
 ----
-The semilocal and hybrid exchange-correlation functionals are unable to describe properly vdW interactions resulting from dynamical correlations between fluctuating charge distributions (called London dispersion forces). A pragmatic way to work around this problem is to add a correction to the conventional Kohn-Sham DFT energy <math>E_{\rm tot}^{\mathrm{KS-DFT}}</math>:
+For fundamental reasons, the semilocal and hybrid exchange-correlation functionals are unable to describe properly vdW interactions resulting from dynamical correlations between fluctuating charge distributions (called London dispersion forces). An approximate way to work around this problem and to get more reliable results for vdW systems is to add a dispersion correction term, <math>E_{\mathrm{disp}}</math>, to the conventional KS-DFT energy <math>E_{\rm tot}^{\mathrm{KS-DFT}}</math>:
 :<math> E_{\rm tot}^{\mathrm{KS-DFT-disp}} = E_{\rm tot}^{\mathrm{KS-DFT}} + E_{\mathrm{disp}}.</math>
-The  correction term <math>E_{\mathrm{disp}}</math> is computed using some of the available approximate methods.
+<math>E_{\mathrm{disp}}</math> can be calculated using one of the available approximate methods listed below.
-The choice of vdW method is controlled via the following tags:
-*{{TAG|IVDW}}=0 no correction
+*{{TAG|IVDW}}=0 : no dispersion correction (default)
-*{{TAG|IVDW}}=1|10 {{TAG|DFT-D2}} method of Grimme (available as of VASP.5.2.11)
+*{{TAG|IVDW}}=1|10 : {{TAG|DFT-D2}} method of Grimme{{cite|grimme:jcc:06}} (available as of VASP.5.2.11)
-*{{TAG|IVDW}}=11 zero damping {{TAG|DFT-D3}} method of Grimme (available as of VASP.5.3.4)
+*{{TAG|IVDW}}=11 : {{TAG|DFT-D3}} method of Grimme with zero-damping function{{cite|grimme:jcp:10}} (available as of VASP.5.3.4)
-*{{TAG|IVDW}}=12 {{TAG|DFT-D3}} method with Becke-Jonson damping (available as of VASP.5.3.4)
+*{{TAG|IVDW}}=12 : {{TAG|DFT-D3}} method with Becke-Johnson damping function{{cite|grimme:jcc:11}} (available as of VASP.5.3.4)
-*{{TAG|IVDW}}=13 DFT-D4 method (available as of VASP.6.2 as [[Installing_VASP.6.X.X#For_DFTD4_.28optional.29|external package]]).
+*{{TAG|IVDW}}=13 : [[DFT-D4]] method{{cite|caldeweyher:jcp:2019}} (available as of VASP.6.2 as [[Makefile.include#DFT-D4_.28optional.29|external package]])
-*{{TAG|IVDW}}=2|20 {{TAG|Tkatchenko-Scheffler method}} (available as of VASP.5.3.3)
+*{{TAG|IVDW}}=14 : One of the methods available in the [[LIBMBD_METHOD|Library libMBD of many-body dispersion methods]]{{cite|libmbd_1}}{{cite|libmbd_2}}{{cite|hermann:jcp:2023}} (available as of VASP.6.4.3 as [[Makefile.include#libMBD_.28optional.29|external package]])
-*{{TAG|IVDW}}=21 {{TAG|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}} (available as of VASP.5.3.5)
+*{{TAG|IVDW}}=2|20 : {{TAG|Tkatchenko-Scheffler method}}{{cite|tkatchenko:prl:09}} (available as of VASP.5.3.3)
-*{{TAG|IVDW}}=202 {{TAG|Many-body dispersion energy}} method (MBD@rSC) (available as of VASP.5.4.1)
+*{{TAG|IVDW}}=21 : {{TAG|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}}{{cite|bucko:jctc:13}}{{cite|bucko:jcp:14}} (available as of VASP.5.3.5)
-*{{TAG|IVDW}}=4 {{TAG|dDsC dispersion correction}} method (available as of VASP.5.4.1)
+*{{TAG|IVDW}}=202 : {{TAG|Many-body dispersion energy}} method (MBD@rSC){{cite|tkatchenko:prl:12}}{{cite|ambrosetti:jcp:14}} (available as of VASP.5.4.1)
+*{{TAG|IVDW}}=263 : {{TAG|Many-body dispersion energy with fractionally ionic model for polarizability}} method (MBD@rSC/FI){{cite|gould:jctc:2016_a}}{{cite|gould:jctc:2016_b}} (available as of VASP.6.1.0)
+*{{TAG|IVDW}}=3 : {{TAG|DFT-ulg}}{{cite|kim:jpcl:2012}} method (available as of VASP.5.3.5)
+*{{TAG|IVDW}}=4 : {{TAG|dDsC dispersion correction}}{{cite|steinmann:jcp:11}}{{cite|steinmann:jctc:11}} method (available as of VASP.5.4.1)
-All methods listed above add vdW correction to  potential energy, interatomic forces, as well as stress tensor and
+With all methods listed above, a dispersion correction is added to the total energy, potential, interatomic forces and stress tensor, such that 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.
-hence simulations such as atomic and lattice relaxations, molecular dynamics, and vibrational
+{{NB|mind|The [[LIBMBD_METHOD|libMBD]] implementations ({{TAG|IVDW}}{{=}}14) of the Tkatchenko-Scheffler methods and their MBD extensions are much faster (analytical calculation of the forces) than the VASP implementations (numerical calculation of the forces). Therefore, it is strongly recommended to use the [[LIBMBD_METHOD|libMBD]] implementation if available.}}
-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 {{TAG|LVDW}} used in previous versions of VASP
+'''N.B.''': The parameter {{TAG|LVDW}} used in previous versions of VASP (5.2.11 and later) to activate the {{TAG|DFT-D2}} method is now obsolete. If {{TAG|LVDW}}=''.TRUE.'' is defined, {{TAG|IVDW}} is automatically set to 1 (unless {{TAG|IVDW}} is specified in {{FILE|INCAR}}).
-(5.2.11 and later) to activate {{TAG|DFT-D2}} method is now obsolete. If {{TAG|LVDW}}=''.TRUE.'' is defined,
-{{TAG|IVDW}} is automatically set to 1 (unless {{TAG|IVDW}} is specified in {{FILE|INCAR}}).
 == Related tags and articles ==
-{{TAG|LVDW}}, {{TAG|DFT-D2}}, {{TAG|DFT-D3}}, {{TAG|Tkatchenko-Scheffler method}},
+{{TAG|DFT-D2}}, {{TAG|DFT-D3}}, [[DFT-D4]],
+{{TAG|Tkatchenko-Scheffler method}},
+{{TAG|Self-consistent screening in Tkatchenko-Scheffler method}},
 {{TAG|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}},
 {{TAG|Many-body dispersion energy}},
-{{TAG|dDsC dispersion correction}}
+{{TAG|Many-body dispersion energy with fractionally ionic model for polarizability}},
+{{TAG|DFT-ulg}},
+{{TAG|dDsC dispersion correction}},
+{{TAG|LIBMBD_METHOD}}
 See also the alternative vdW-DF functionals: {{TAG|LUSE_VDW}}, {{TAG|Nonlocal vdW-DF functionals}}.