DFT-D4 - Revision history

Ftran at 16:40, 5 March 2026

2026-03-05T16:40:16Z

← Older revision		Revision as of 16:40, 5 March 2026
Line 1:		Line 1:
	DFT-D4{{cite\|caldeweyher:jcp:2019}}{{cite\|dftd4_1}}{{cite\|dftd4_2}} is an external package that can be [[Makefile.include#DFT-~~D4_~~.28optional.29\|linked to VASP]]. DFT-D4 adds to the DFT energy expression a term that accounts for the [[:Category:Van der Waals functionals\|van der Waals (vdW) interactions]], which are in principle not included in semilocal and hybrid exchange-correlation functionals.		DFT-D4{{cite\|caldeweyher:jcp:2019}}{{cite\|dftd4_1}}{{cite\|dftd4_2}} is an external package that can be [[Makefile.include#DFT-D4 and simple-DFT-D3_.28optional.29\|linked to VASP]]. DFT-D4 adds to the DFT energy expression a term that accounts for the [[:Category:Van der Waals functionals\|van der Waals (vdW) interactions]], which are in principle not included in semilocal and hybrid exchange-correlation functionals.
	This is an approximation of the atom-pairwise type that depends only on the structure of the system, which allows for a fast computation.		This is an approximation of the atom-pairwise type that depends only on the structure of the system, which allows for a fast computation.
	Since every functional has different interactions between atoms, DFT-D4 tailors its adjustable parameters to the functional.		Since every functional has different interactions between atoms, DFT-D4 tailors its adjustable parameters to the functional.
Line 11:		Line 11:
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|important\|		{{NB\|important\|
	*The API of DFT-D4 has been modified starting with version 4.0.0. The adaptation has been made in VASP.6.6.0. Versions of DFT-D4 with the old API (v3.7.0 and older) can still be compiled with VASP.6.6.0 as explained [[Makefile.include#DFT-~~D4_~~.28optional.29\|here]].		*The API of DFT-D4 has been modified starting with version 4.0.0. The adaptation has been made in VASP.6.6.0. Versions of DFT-D4 with the old API (v3.7.0 and older) can still be compiled with VASP.6.6.0 as explained [[Makefile.include#DFT-D4 and simple-DFT-D3_.28optional.29\|here]].
	*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.		*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.
	}}		}}
Line 41:		Line 41:
	{{TAG\|VDW_CNRADIUS}},		{{TAG\|VDW_CNRADIUS}},
	[[DFT-D3]],		[[DFT-D3]],
	[[simple-DFT-D3~~]],~~		[[simple-DFT-D3]]
	~~[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4~~]]

	[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]		[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]

Miranda.henrique: /* Usage */

2026-03-05T13:43:56Z

Usage

← Older revision		Revision as of 13:43, 5 March 2026
Line 11:		Line 11:
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|important\|		{{NB\|important\|
	*The API of DFT-D4 has been modified starting with version 4.0.0. The adaptation has been made in VASP.6.0.0. Versions of DFT-D4 with the old API (v3.7.0 and older) can still be compiled with VASP.6.0.0 as explained [[Makefile.include#DFT-D4_.28optional.29\|here]].		*The API of DFT-D4 has been modified starting with version 4.0.0. The adaptation has been made in VASP.6.6.0. Versions of DFT-D4 with the old API (v3.7.0 and older) can still be compiled with VASP.6.6.0 as explained [[Makefile.include#DFT-D4_.28optional.29\|here]].
	*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.		*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.
	}}		}}

Ftran at 11:08, 2 March 2026

2026-03-02T11:08:31Z

← Older revision		Revision as of 11:08, 2 March 2026
Line 1:		Line 1:
	DFT-D4 is an external package ~~maintained by the Grimme group~~ that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]].		DFT-D4{{cite\|caldeweyher:jcp:2019}}{{cite\|dftd4_1}}{{cite\|dftd4_2}} is an external package that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]]. DFT-D4 adds to the DFT energy expression a term that accounts for the [[:Category:Van der Waals functionals\|van der Waals (vdW) interactions]], which are in principle not included in semilocal and hybrid exchange-correlation functionals.
	~~Read the [https://dftd4.readthedocs.io/en/latest/ documentation] for more information about this package.~~		This is an approximation of the atom-pairwise type that depends only on the structure of the system, which allows for a fast computation.
	DFT-D4 adds [[:Category:Van der Waals functionals\|van-der-Waals (vdW) interactions]] ~~to DFT because they~~ are not included in ~~most~~ exchange-correlation functionals.
	~~It approximates~~ the ~~vdW interactions considering~~ only the structure of the system which allows for a fast computation.
	Since every functional has different interactions between atoms, DFT-D4 tailors its adjustable parameters to the functional.		Since every functional has different interactions between atoms, DFT-D4 tailors its adjustable parameters to the functional.
			For more information regarding these parameters, please refer to the DFT-D4 paper{{cite\|caldeweyher:jcp:2019}} and websites.{{cite\|dftd4_1}}{{cite\|dftd4_2}}
	For more information regarding these parameters, please refer to the DFT-D4 paper.{{cite\|caldeweyher:~~pccp~~:~~2020~~}}

	== Usage ==		== Usage ==

	~~In most cases~~, it is sufficient to set {{TAG\|IVDW}}=13 in the {{FILE\|INCAR}} file if VASP ~~was [[Makefile.include#~~DFT-~~D4_~~.~~28optional.29~~\|~~compiled and linked~~ to DFT-D4]].		For some of the common exchange-correlation functionals (e.g., PBE, SCAN, or HSE06) it is sufficient to set {{TAG\|IVDW}}=13 in the {{FILE\|INCAR}} file. Internally, VASP passes automatically the name of the functional to DFT-D4. However, for other functionals the {{TAG\|DFTD4_XC}} tag has to be used to specify the functional to DFT-D4 (the names are listed in the file param.f90 of the DFT-D4 source code).
	~~Internally, VASP passes the name~~ of the ~~used exchange-correlation functional to~~ DFT-D4.		Subsequently, DFT-D4 maps the functional name to optimized settings for the adjustable parameters of the vdW interaction.
	Subsequently, DFT-D4 maps ~~this name of~~ the functional to optimized settings for the adjustable parameters of the vdW interaction.
	VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.		VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|~~warning~~\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|important\|
			*The API of DFT-D4 has been modified starting with version 4.0.0. The adaptation has been made in VASP.6.0.0. Versions of DFT-D4 with the old API (v3.7.0 and older) can still be compiled with VASP.6.0.0 as explained [[Makefile.include#DFT-D4_.28optional.29\|here]].
	~~VASP allows setting the following tags in the {{FILE\|INCAR~~}} ~~file to change the strength of the vdW interaction.~~		*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.
			}}

	* {{TAG\|~~VDW_S6~~}}, {{TAG\|~~VDW_S8~~}} determine the ~~strength~~ of the dipole-dipole ~~and~~ dipole-quadrupole ~~interaction~~.		VASP allows setting the following tags in the {{FILE\|INCAR}} file:
	* {{TAG\|VDW_A1}}, {{TAG\|VDW_A2}} ~~are scaling constants~~ in the Becke-Johnson damping.		* {{TAG\|DFTD4_MODEL}} : dispersion model (available from VASP.6.6.0 onwards).
			* {{TAG\|DFTD4_XC}} : functional name to determine the set of vdW parameters (available from VASP.6.6.0 onwards).
			* {{TAG\|VDW_S6}} : scaling of the dipole-dipole dispersion.
			* {{TAG\|VDW_S8}} : scaling of the dipole-quadrupole dispersion.
			* {{TAG\|VDW_A1}} : scaling of the critical radii in the Becke-Johnson rational damping.
			* {{TAG\|VDW_A2}} : offset of the critical radii in the Becke-Johnson rational damping.
			* {{TAG\|VDW_S9}} : scaling of the three-body dispersion energy (available from VASP.6.6.0 onwards).
			* {{TAG\|VDW_RADIUS}} : two-body interaction cutoff (available from VASP.6.6.0 onwards).
			* {{TAG\|VDW_CNRADIUS}} : coordination number cutoff (available from VASP.6.6.0 onwards).

	== References ==		== References ==
Line 26:		Line 31:
	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|IVDW}},		{{TAG\|IVDW}},
			{{TAG\|DFTD4_MODEL}},
			{{TAG\|DFTD4_XC}},
	{{TAG\|VDW_S6}},		{{TAG\|VDW_S6}},
	{{TAG\|VDW_S8}},		{{TAG\|VDW_S8}},
	{{TAG\|VDW_A1}},		{{TAG\|VDW_A1}},
	{{TAG\|VDW_A2}},		{{TAG\|VDW_A2}},
			{{TAG\|VDW_S9}},
			{{TAG\|VDW_RADIUS}},
			{{TAG\|VDW_CNRADIUS}},
	[[DFT-D3]],		[[DFT-D3]],
			[[simple-DFT-D3]],
	[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]		[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]

	[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]		[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]

Ftran: Undo revision 33696 by Ftran (talk)

2026-02-02T10:36:59Z

Undo revision 33696 by Ftran (talk)

← Older revision		Revision as of 10:36, 2 February 2026
Line 15:		Line 15:
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}
	{{NB\|important\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.

Ftran: Undo revision 33697 by Ftran (talk)

2026-02-02T10:36:52Z

Undo revision 33697 by Ftran (talk)

← Older revision		Revision as of 10:36, 2 February 2026
Line 14:		Line 14:
	VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.		VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|~~important~~\|		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}
	*There is a change in the ~~API~~ of DFT-D4 ~~since version 4~~.0.0.		{{NB\|important\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}
	*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.
	}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.

Ftran at 10:31, 2 February 2026

2026-02-02T10:31:49Z

← Older revision		Revision as of 10:31, 2 February 2026
Line 14:		Line 14:
	VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.		VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|~~warning~~\|~~Below, we explain how to tweak~~ the ~~parameters~~ of DFT-D4. ~~Typically, you should not modify them unless you have a very good reason, e.g~~.~~, because the interface is not implemented for the exchange-correlation functional you use~~.}}		{{NB\|important\|
	~~{{NB\|important\|~~Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		*There is a change in the API of DFT-D4 since version 4.0.0.
			*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.
			}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.

Ftran at 10:29, 2 February 2026

2026-02-02T10:29:41Z

← Older revision		Revision as of 10:29, 2 February 2026
Line 15:		Line 15:
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}
			{{NB\|important\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.

Ftran: Undo revision 33403 by Ftran (talk)

2026-01-30T09:40:53Z

Undo revision 33403 by Ftran (talk)

← Older revision		Revision as of 09:40, 30 January 2026
Line 1:		Line 1:
	DFT-D4 is an external package that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]].		DFT-D4 is an external package maintained by the Grimme group that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]].
	Read the [https://dftd4.readthedocs.io/en/latest/ documentation] for more information about this package.		Read the [https://dftd4.readthedocs.io/en/latest/ documentation] for more information about this package.
	DFT-D4 adds [[:Category:Van der Waals functionals\|van-der-Waals (vdW) interactions]] to DFT because they are not included in most exchange-correlation functionals.		DFT-D4 adds [[:Category:Van der Waals functionals\|van-der-Waals (vdW) interactions]] to DFT because they are not included in most exchange-correlation functionals.
Line 16:		Line 16:
	{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the vdW ~~parameters used in DFT-D4~~.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.
	* {{TAG\|~~DFTD4_MODEL~~}} ~~: Dispersion model (available from VASP.6.6.0 onwards).~~
	* {{TAG\|~~DFTD4_XC~~}} ~~: Functional name to~~ determine the ~~set of vdW parameters (available from VASP.6.6.0 onwards).~~		* {{TAG\|VDW_S6}}, {{TAG\|VDW_S8}} determine the strength of the dipole-dipole and dipole-quadrupole interaction.
	* {{TAG\|VDW_S6}} : Scaling of the dipole-dipole ~~dispersion.~~		* {{TAG\|VDW_A1}}, {{TAG\|VDW_A2}} are scaling constants in the Becke-Johnson damping.
	* {{TAG\|VDW_S8}} : Scaling of the dipole-quadrupole ~~dispersion~~.
	* {{TAG\|VDW_A1}} ~~: Scaling of the critical radii in the Becke-Johnson rational damping.~~
	* {{TAG\|VDW_A2}} ~~: Offset of the critical radii~~ in the Becke-Johnson ~~rational~~ damping.
	* {{TAG\|VDW_S9}} : Scaling of the three-body dispersion energy (available from VASP.6.6.0 onwards).
	* {{TAG\|VDW_RADIUS}} : two-body interaction cutoff (available from VASP.6.6.0 onwards).
	* {{TAG\|VDW_CNRADIUS}} : coordination number cutoff (available from VASP.6.6.0 onwards).

	== References ==		== References ==
Line 32:		Line 26:
	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|IVDW}},		{{TAG\|IVDW}},
	~~{{TAG\|DFTD4_MODEL}},~~
	~~{{TAG\|DFTD4_XC}},~~
	{{TAG\|VDW_S6}},		{{TAG\|VDW_S6}},
	{{TAG\|VDW_S8}},		{{TAG\|VDW_S8}},
	{{TAG\|VDW_A1}},		{{TAG\|VDW_A1}},
	{{TAG\|VDW_A2}},		{{TAG\|VDW_A2}},
	~~{{TAG\|VDW_RADIUS}},~~
	~~{{TAG\|VDW_CNRADIUS}},~~
	[[DFT-D3]],		[[DFT-D3]],
	~~[[simple DFT-D3]],~~
	[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]		[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]

	[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]		[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]

Ftran: Undo revision 33404 by Ftran (talk)

2026-01-30T09:40:36Z

Undo revision 33404 by Ftran (talk)

← Older revision		Revision as of 09:40, 30 January 2026
Line 38:		Line 38:
	{{TAG\|VDW_A1}},		{{TAG\|VDW_A1}},
	{{TAG\|VDW_A2}},		{{TAG\|VDW_A2}},
	~~{{TAG\|VDW_S9}},~~
	{{TAG\|VDW_RADIUS}},		{{TAG\|VDW_RADIUS}},
	{{TAG\|VDW_CNRADIUS}},		{{TAG\|VDW_CNRADIUS}},

Ftran: Undo revision 33417 by Ftran (talk)

2026-01-30T09:40:01Z

Undo revision 33417 by Ftran (talk)

← Older revision		Revision as of 09:40, 30 January 2026
Line 16:		Line 16:
	{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the vdW parameters used in ~~the~~ DFT-D4 ~~package~~.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the vdW parameters used in DFT-D4.
	* {{TAG\|DFTD4_MODEL}} : Dispersion model (available from VASP.6.6.0 onwards).		* {{TAG\|DFTD4_MODEL}} : Dispersion model (available from VASP.6.6.0 onwards).
	* {{TAG\|DFTD4_XC}} : Functional name to determine the set of vdW parameters (available from VASP.6.6.0 onwards).		* {{TAG\|DFTD4_XC}} : Functional name to determine the set of vdW parameters (available from VASP.6.6.0 onwards).

← Older revision		Revision as of 11:08, 2 March 2026
Line 1:		Line 1:
	DFT-D4 is an external package ~~maintained by the Grimme group~~ that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]].		DFT-D4{{cite\|caldeweyher:jcp:2019}}{{cite\|dftd4_1}}{{cite\|dftd4_2}} is an external package that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]]. DFT-D4 adds to the DFT energy expression a term that accounts for the [[:Category:Van der Waals functionals\|van der Waals (vdW) interactions]], which are in principle not included in semilocal and hybrid exchange-correlation functionals.
	~~Read the [https://dftd4.readthedocs.io/en/latest/ documentation] for more information about this package.~~		This is an approximation of the atom-pairwise type that depends only on the structure of the system, which allows for a fast computation.
	DFT-D4 adds [[:Category:Van der Waals functionals\|van-der-Waals (vdW) interactions]] ~~to DFT because they~~ are not included in ~~most~~ exchange-correlation functionals.
	~~It approximates~~ the ~~vdW interactions considering~~ only the structure of the system which allows for a fast computation.
	Since every functional has different interactions between atoms, DFT-D4 tailors its adjustable parameters to the functional.		Since every functional has different interactions between atoms, DFT-D4 tailors its adjustable parameters to the functional.
			For more information regarding these parameters, please refer to the DFT-D4 paper{{cite\|caldeweyher:jcp:2019}} and websites.{{cite\|dftd4_1}}{{cite\|dftd4_2}}
	For more information regarding these parameters, please refer to the DFT-D4 paper.{{cite\|caldeweyher:~~pccp~~:~~2020~~}}

	== Usage ==		== Usage ==

	~~In most cases~~, it is sufficient to set {{TAG\|IVDW}}=13 in the {{FILE\|INCAR}} file if VASP ~~was [[Makefile.include#~~DFT-~~D4_~~.~~28optional.29~~\|~~compiled and linked~~ to DFT-D4]].		For some of the common exchange-correlation functionals (e.g., PBE, SCAN, or HSE06) it is sufficient to set {{TAG\|IVDW}}=13 in the {{FILE\|INCAR}} file. Internally, VASP passes automatically the name of the functional to DFT-D4. However, for other functionals the {{TAG\|DFTD4_XC}} tag has to be used to specify the functional to DFT-D4 (the names are listed in the file param.f90 of the DFT-D4 source code).
	~~Internally, VASP passes the name~~ of the ~~used exchange-correlation functional to~~ DFT-D4.		Subsequently, DFT-D4 maps the functional name to optimized settings for the adjustable parameters of the vdW interaction.
	Subsequently, DFT-D4 maps ~~this name of~~ the functional to optimized settings for the adjustable parameters of the vdW interaction.
	VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.		VASP uses these parameters to compute the DFT-D4 energies, forces, and stresses in every ionic step and adds them to the corresponding DFT terms.
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|~~warning~~\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|important\|
			*The API of DFT-D4 has been modified starting with version 4.0.0. The adaptation has been made in VASP.6.0.0. Versions of DFT-D4 with the old API (v3.7.0 and older) can still be compiled with VASP.6.0.0 as explained [[Makefile.include#DFT-D4_.28optional.29\|here]].
	~~VASP allows setting the following tags in the {{FILE\|INCAR~~}} ~~file to change the strength of the vdW interaction.~~		*Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.
			}}

	* {{TAG\|~~VDW_S6~~}}, {{TAG\|~~VDW_S8~~}} determine the ~~strength~~ of the dipole-dipole ~~and~~ dipole-quadrupole ~~interaction~~.		VASP allows setting the following tags in the {{FILE\|INCAR}} file:
	* {{TAG\|VDW_A1}}, {{TAG\|VDW_A2}} ~~are scaling constants~~ in the Becke-Johnson damping.		* {{TAG\|DFTD4_MODEL}} : dispersion model (available from VASP.6.6.0 onwards).
			* {{TAG\|DFTD4_XC}} : functional name to determine the set of vdW parameters (available from VASP.6.6.0 onwards).
			* {{TAG\|VDW_S6}} : scaling of the dipole-dipole dispersion.
			* {{TAG\|VDW_S8}} : scaling of the dipole-quadrupole dispersion.
			* {{TAG\|VDW_A1}} : scaling of the critical radii in the Becke-Johnson rational damping.
			* {{TAG\|VDW_A2}} : offset of the critical radii in the Becke-Johnson rational damping.
			* {{TAG\|VDW_S9}} : scaling of the three-body dispersion energy (available from VASP.6.6.0 onwards).
			* {{TAG\|VDW_RADIUS}} : two-body interaction cutoff (available from VASP.6.6.0 onwards).
			* {{TAG\|VDW_CNRADIUS}} : coordination number cutoff (available from VASP.6.6.0 onwards).

	== References ==		== References ==
Line 26:		Line 31:
	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|IVDW}},		{{TAG\|IVDW}},
			{{TAG\|DFTD4_MODEL}},
			{{TAG\|DFTD4_XC}},
	{{TAG\|VDW_S6}},		{{TAG\|VDW_S6}},
	{{TAG\|VDW_S8}},		{{TAG\|VDW_S8}},
	{{TAG\|VDW_A1}},		{{TAG\|VDW_A1}},
	{{TAG\|VDW_A2}},		{{TAG\|VDW_A2}},
			{{TAG\|VDW_S9}},
			{{TAG\|VDW_RADIUS}},
			{{TAG\|VDW_CNRADIUS}},
	[[DFT-D3]],		[[DFT-D3]],
			[[simple-DFT-D3]],
	[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]		[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]

	[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]		[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]

← Older revision		Revision as of 10:36, 2 February 2026
Line 15:		Line 15:
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}
	{{NB\|important\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.

← Older revision		Revision as of 10:29, 2 February 2026
Line 15:		Line 15:
	As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.		As a result, you can relax structures or run [[MD\|MD simulations]] with an approximate treatment of vdW interactions.
	{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}
			{{NB\|important\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.

← Older revision		Revision as of 09:40, 30 January 2026
Line 1:		Line 1:
	DFT-D4 is an external package that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]].		DFT-D4 is an external package maintained by the Grimme group that can be [[Makefile.include#DFT-D4_.28optional.29\|linked to VASP]].
	Read the [https://dftd4.readthedocs.io/en/latest/ documentation] for more information about this package.		Read the [https://dftd4.readthedocs.io/en/latest/ documentation] for more information about this package.
	DFT-D4 adds [[:Category:Van der Waals functionals\|van-der-Waals (vdW) interactions]] to DFT because they are not included in most exchange-correlation functionals.		DFT-D4 adds [[:Category:Van der Waals functionals\|van-der-Waals (vdW) interactions]] to DFT because they are not included in most exchange-correlation functionals.
Line 16:		Line 16:
	{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}		{{NB\|warning\|Below, we explain how to tweak the parameters of DFT-D4. Typically, you should not modify them unless you have a very good reason, e.g., because the interface is not implemented for the exchange-correlation functional you use.}}

	VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the vdW ~~parameters used in DFT-D4~~.		VASP allows setting the following tags in the {{FILE\|INCAR}} file to change the strength of the vdW interaction.
	* {{TAG\|~~DFTD4_MODEL~~}} ~~: Dispersion model (available from VASP.6.6.0 onwards).~~
	* {{TAG\|~~DFTD4_XC~~}} ~~: Functional name to~~ determine the ~~set of vdW parameters (available from VASP.6.6.0 onwards).~~		* {{TAG\|VDW_S6}}, {{TAG\|VDW_S8}} determine the strength of the dipole-dipole and dipole-quadrupole interaction.
	* {{TAG\|VDW_S6}} : Scaling of the dipole-dipole ~~dispersion.~~		* {{TAG\|VDW_A1}}, {{TAG\|VDW_A2}} are scaling constants in the Becke-Johnson damping.
	* {{TAG\|VDW_S8}} : Scaling of the dipole-quadrupole ~~dispersion~~.
	* {{TAG\|VDW_A1}} ~~: Scaling of the critical radii in the Becke-Johnson rational damping.~~
	* {{TAG\|VDW_A2}} ~~: Offset of the critical radii~~ in the Becke-Johnson ~~rational~~ damping.
	* {{TAG\|VDW_S9}} : Scaling of the three-body dispersion energy (available from VASP.6.6.0 onwards).
	* {{TAG\|VDW_RADIUS}} : two-body interaction cutoff (available from VASP.6.6.0 onwards).
	* {{TAG\|VDW_CNRADIUS}} : coordination number cutoff (available from VASP.6.6.0 onwards).

	== References ==		== References ==
Line 32:		Line 26:
	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|IVDW}},		{{TAG\|IVDW}},
	~~{{TAG\|DFTD4_MODEL}},~~
	~~{{TAG\|DFTD4_XC}},~~
	{{TAG\|VDW_S6}},		{{TAG\|VDW_S6}},
	{{TAG\|VDW_S8}},		{{TAG\|VDW_S8}},
	{{TAG\|VDW_A1}},		{{TAG\|VDW_A1}},
	{{TAG\|VDW_A2}},		{{TAG\|VDW_A2}},
	~~{{TAG\|VDW_RADIUS}},~~
	~~{{TAG\|VDW_CNRADIUS}},~~
	[[DFT-D3]],		[[DFT-D3]],
	~~[[simple DFT-D3]],~~
	[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]		[[Makefile.include#DFT-D4_.28optional.29\|Linking to DFT-D4]]

	[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]		[[Category:Exchange-correlation functionals]][[Category:Van der Waals functionals]][[Category:Howto]]

← Older revision		Revision as of 09:40, 30 January 2026
Line 38:		Line 38:
	{{TAG\|VDW_A1}},		{{TAG\|VDW_A1}},
	{{TAG\|VDW_A2}},		{{TAG\|VDW_A2}},
	~~{{TAG\|VDW_S9}},~~
	{{TAG\|VDW_RADIUS}},		{{TAG\|VDW_RADIUS}},
	{{TAG\|VDW_CNRADIUS}},		{{TAG\|VDW_CNRADIUS}},