Many-body dispersion energy - Revision history

Ftran at 14:56, 6 March 2025

2025-03-06T14:56:00Z

← Older revision		Revision as of 14:56, 6 March 2025
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	where <math>{\mathbf{A}}_{LR}</math> is the frequency-dependent polarizability matrix and <math>\mathbf{T}_{LR}</math> is the long-range interaction tensor, which describes the interaction of the screened polarizabilities		where <math>{\mathbf{A}}_{LR}</math> is the frequency-dependent polarizability matrix and <math>\mathbf{T}_{LR}</math> is the long-range interaction tensor, which describes the interaction of the screened polarizabilities
	embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see		embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see
	references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details). The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}		references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details).

			Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.

			== Usage ==
			The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}
	(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file.		(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file.

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	<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> for details		<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> for details

	~~Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.~~
	{{NB\|mind\|		{{NB\|mind\|
	*This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.		*This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.

Ftran at 10:26, 28 February 2025

2025-02-28T10:26:12Z

← Older revision		Revision as of 10:26, 28 February 2025
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	----		----

	[[Category:Exchange-correlation functionals]][[Category:van der Waals functionals]][[Category:Theory]]		[[Category:Exchange-correlation functionals]][[Category:van der Waals functionals]][[Category:Theory]][[Category:Howto]]

Ftran at 10:36, 24 February 2025

2025-02-24T10:36:28Z

← Older revision		Revision as of 10:36, 24 February 2025
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	The many-body dispersion energy method (MBD@rsSCS) of Tkatchenko et al.{{cite\|tkatchenko:prl:12}}{{cite\|ambrosetti:jcp:14}} is based on the random-phase expression for the correlation energy		The many-body dispersion energy method (MBD@rsSCS) of Tkatchenko et al.,{{cite\|tkatchenko:prl:12}}{{cite\|ambrosetti:jcp:14}} invoked by setting {{TAG\|IVDW}}=202, is based on the random-phase expression for the correlation energy

	:<math> E_c = \int_{0}^{\infty} \frac{d\omega}{2\pi} \mathrm{Tr}\left\{\mathrm{ln} (1-v\chi_0(i\omega))+v\chi_0(i\omega) \right\} </math>		:<math> E_c = \int_{0}^{\infty} \frac{d\omega}{2\pi} \mathrm{Tr}\left\{\mathrm{ln} (1-v\chi_0(i\omega))+v\chi_0(i\omega) \right\} </math>
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	embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see		embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see
	references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details). The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}		references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details). The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}
	(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file. The ~~MBD@rsSCS method is invoked by setting {{TAG\|IVDW}}=202. Optionally, the~~ following parameters can be user-defined (the given values are the default ones):		(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file.

			The following optional parameters can be user-defined (the given values are the default ones):

	*{{TAG\|VDW_SR}}=0.83 : scaling parameter <math>\beta</math>		*{{TAG\|VDW_SR}}=0.83 : scaling parameter <math>\beta</math>

Ftran at 12:02, 20 May 2024

2024-05-20T12:02:09Z

← Older revision		Revision as of 12:02, 20 May 2024
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	*Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.		*Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.
	*Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.		*Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.
	*A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 (({{TAG\|VDW_SR}}{{=}}0.85)), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}		*A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 ({{TAG\|VDW_SR}}{{=}}0.85), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}

	== Related tags and articles ==		== Related tags and articles ==

Ftran at 08:58, 20 October 2023

2023-10-20T08:58:07Z

← Older revision		Revision as of 08:58, 20 October 2023
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	----		----
	~~[[The_VASP_Manual\|Contents]]~~
	[[Category:Exchange-correlation functionals]][[Category:van der Waals functionals]][[Category:Theory]]		[[Category:Exchange-correlation functionals]][[Category:van der Waals functionals]][[Category:Theory]]

Ftran at 14:51, 12 October 2023

2023-10-12T14:51:34Z

← Older revision		Revision as of 14:51, 12 October 2023
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	Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.		Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.
	{{NB\|mind\|This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.}}		{{NB\|mind\|
	~~{{NB\|mind\|~~The input reference data for non-interacting atoms are available only for elements of the first six rows of the periodic table except of the lanthanides. If the system contains other elements, the user has to provide the free-atomic parameters for all atoms in the system via {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}} and {{TAG\|VDW_R0}} (described by the {{TAG\|Tkatchenko-Scheffler method}}) defined in the {{TAG\|INCAR}} file.}}		*This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.
	~~{{NB\|mind\|~~The charge-density dependence of gradients is neglected.}}		*The input reference data for non-interacting atoms are available only for elements of the first six rows of the periodic table except of the lanthanides. If the system contains other elements, the user has to provide the free-atomic parameters for all atoms in the system via {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}} and {{TAG\|VDW_R0}} (described by the {{TAG\|Tkatchenko-Scheffler method}}) defined in the {{TAG\|INCAR}} file.
	~~{{NB\|mind\|~~This method is incompatible with the setting {{TAG\|ADDGRID}}{{=}}''.TRUE.''.}}		*The charge-density dependence of gradients is neglected.
	~~{{NB\|mind\|~~It is essential that a sufficiently dense FFT grid (controlled via {{TAG\|NGXF}}, {{TAG\|NGYF}} and {{TAG\|NGZF}} ) is used in the {{TAG\|Tkatchenko-Scheffler method}} calculation. We strongly recommend to use {{TAG\|PREC}}{{=}}''Accurate'' for this type of calculations (in any case, avoid using {{TAG\|PREC}}{{=}}''Low''}).}}		*This method is incompatible with the setting {{TAG\|ADDGRID}}{{=}}''.TRUE.''.
	~~{{NB\|mind\|~~The method sometimes has numerical problems if highly polarizable atoms are located at short distances. In such a case the calculation terminates with an error message ''Error(vdw\_tsscs\_range\_separated\_k): d\_lr(pp)<{{=}}0''. Note that this problem is not caused by a bug, but rather it is due to a limitation of the underlying physical model.}}		*It is essential that a sufficiently dense FFT grid (controlled via {{TAG\|NGXF}}, {{TAG\|NGYF}} and {{TAG\|NGZF}} ) is used in the {{TAG\|Tkatchenko-Scheffler method}} calculation. We strongly recommend to use {{TAG\|PREC}}{{=}}''Accurate'' for this type of calculations (in any case, avoid using {{TAG\|PREC}}{{=}}''Low'').
	~~{{NB\|mind\|~~Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.}}		*The method sometimes has numerical problems if highly polarizable atoms are located at short distances. In such a case the calculation terminates with an error message ''Error(vdw\_tsscs\_range\_separated\_k): d\_lr(pp)<{{=}}0''. Note that this problem is not caused by a bug, but rather it is due to a limitation of the underlying physical model.
	~~{{NB\|mind\|~~Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.}}		*Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.
	~~{{NB\|mind\|~~A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 (({{TAG\|VDW_SR}}{{=}}0.85)), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}		*Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.
			*A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 (({{TAG\|VDW_SR}}{{=}}0.85)), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}

	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|VDW_ALPHA}},		{{TAG\|VDW_ALPHA}},

Huebsch at 07:50, 26 September 2023

2023-09-26T07:50:34Z

Ftran at 20:05, 1 February 2023

2023-02-01T20:05:08Z

← Older revision		Revision as of 20:05, 1 February 2023
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	{{TAG\|LSCSGRAD}},		{{TAG\|LSCSGRAD}},
	{{TAG\|IVDW}},		{{TAG\|IVDW}},
	~~{{TAG\|IALGO}},~~
	{{TAG\|Tkatchenko-Scheffler method}},		{{TAG\|Tkatchenko-Scheffler method}},
			{{TAG\|Self-consistent screening in Tkatchenko-Scheffler method}},
	{{TAG\|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}},		{{TAG\|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}},
	{{TAG\|~~Self~~-~~consistent screening in Tkatchenko-Scheffler method~~}}		{{TAG\|Many-body dispersion energy with fractionally ionic model for polarizability}}

	== References ==		== References ==

Ftran at 19:46, 1 February 2023

2023-02-01T19:46:25Z

← Older revision		Revision as of 19:46, 1 February 2023
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	{{TAG\|IVDW}},		{{TAG\|IVDW}},
	{{TAG\|IALGO}},		{{TAG\|IALGO}},
	~~{{TAG\|DFT-D2}},~~
	~~{{TAG\|DFT-D3}},~~
	{{TAG\|Tkatchenko-Scheffler method}},		{{TAG\|Tkatchenko-Scheffler method}},
	{{TAG\|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}},		{{TAG\|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}},
	{{TAG\|Self-consistent screening in Tkatchenko-Scheffler method~~}},~~		{{TAG\|Self-consistent screening in Tkatchenko-Scheffler method}}
	~~{{TAG\|dDsC dispersion correction~~}}

	== References ==		== References ==

Tbucko at 11:16, 4 November 2022

2022-11-04T11:16:39Z

← Older revision		Revision as of 11:16, 4 November 2022
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	*{{TAG\|LSCSGRAD}}=.TRUE. : compute gradients (or not)		*{{TAG\|LSCSGRAD}}=.TRUE. : compute gradients (or not)
	*{{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, {{TAG\|VDW_R0}} : atomic reference (see alse {{TAG\|Tkatchenko-Scheffler method}})		*{{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, {{TAG\|VDW_R0}} : atomic reference (see alse {{TAG\|Tkatchenko-Scheffler method}})
	*ITIM=-1: if set to +1, apply eigenvalue remapping to avoid unphysical cases where the eigenvalues of the matrix		*{{TAG\|ITIM}}=-1: if set to +1, apply eigenvalue remapping to avoid unphysical cases where the eigenvalues of the matrix
	<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> fore details		<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> fore details

← Older revision		Revision as of 14:56, 6 March 2025
Line 9:		Line 9:
	where <math>{\mathbf{A}}_{LR}</math> is the frequency-dependent polarizability matrix and <math>\mathbf{T}_{LR}</math> is the long-range interaction tensor, which describes the interaction of the screened polarizabilities		where <math>{\mathbf{A}}_{LR}</math> is the frequency-dependent polarizability matrix and <math>\mathbf{T}_{LR}</math> is the long-range interaction tensor, which describes the interaction of the screened polarizabilities
	embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see		embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see
	references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details). The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}		references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details).

			Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.

			== Usage ==
			The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}
	(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file.		(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file.

Line 21:		Line 26:
	<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> for details		<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> for details

	~~Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.~~
	{{NB\|mind\|		{{NB\|mind\|
	*This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.		*This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.

← Older revision		Revision as of 10:36, 24 February 2025
Line 1:		Line 1:
	The many-body dispersion energy method (MBD@rsSCS) of Tkatchenko et al.{{cite\|tkatchenko:prl:12}}{{cite\|ambrosetti:jcp:14}} is based on the random-phase expression for the correlation energy		The many-body dispersion energy method (MBD@rsSCS) of Tkatchenko et al.,{{cite\|tkatchenko:prl:12}}{{cite\|ambrosetti:jcp:14}} invoked by setting {{TAG\|IVDW}}=202, is based on the random-phase expression for the correlation energy

	:<math> E_c = \int_{0}^{\infty} \frac{d\omega}{2\pi} \mathrm{Tr}\left\{\mathrm{ln} (1-v\chi_0(i\omega))+v\chi_0(i\omega) \right\} </math>		:<math> E_c = \int_{0}^{\infty} \frac{d\omega}{2\pi} \mathrm{Tr}\left\{\mathrm{ln} (1-v\chi_0(i\omega))+v\chi_0(i\omega) \right\} </math>
Line 10:		Line 10:
	embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see		embedded in the system in a given geometrical arrangement. The components of <math>\mathbf{A}_{LR}</math> are obtained using an atoms-in-molecule approach as employed in the pairwise {{TAG\|Tkatchenko-Scheffler method}} (see
	references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details). The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}		references {{cite\|ambrosetti:jcp:14}}{{cite\|bucko:jpcm:16}} for details). The input reference data for non-interacting atoms can be optionally defined via the parameters {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, and {{TAG\|VDW_R0}}
	(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file. The ~~MBD@rsSCS method is invoked by setting {{TAG\|IVDW}}=202. Optionally, the~~ following parameters can be user-defined (the given values are the default ones):		(described by the {{TAG\|Tkatchenko-Scheffler method}}). This method has one free parameter (<math>\beta</math>) that must be adjusted for each exchange-correlation functional. The default value of <math>\beta</math>=0.83 corresponds to the PBE functional ({{TAG\|GGA}}{{=}}PE). If another functional is used, the value of <math>\beta</math> must be specified via {{TAG\|VDW_SR}} in the {{TAG\|INCAR}} file.

			The following optional parameters can be user-defined (the given values are the default ones):

	*{{TAG\|VDW_SR}}=0.83 : scaling parameter <math>\beta</math>		*{{TAG\|VDW_SR}}=0.83 : scaling parameter <math>\beta</math>

← Older revision		Revision as of 14:51, 12 October 2023
Line 20:		Line 20:

	Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.		Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.
	{{NB\|mind\|This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.}}		{{NB\|mind\|
	~~{{NB\|mind\|~~The input reference data for non-interacting atoms are available only for elements of the first six rows of the periodic table except of the lanthanides. If the system contains other elements, the user has to provide the free-atomic parameters for all atoms in the system via {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}} and {{TAG\|VDW_R0}} (described by the {{TAG\|Tkatchenko-Scheffler method}}) defined in the {{TAG\|INCAR}} file.}}		*This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.
	~~{{NB\|mind\|~~The charge-density dependence of gradients is neglected.}}		*The input reference data for non-interacting atoms are available only for elements of the first six rows of the periodic table except of the lanthanides. If the system contains other elements, the user has to provide the free-atomic parameters for all atoms in the system via {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}} and {{TAG\|VDW_R0}} (described by the {{TAG\|Tkatchenko-Scheffler method}}) defined in the {{TAG\|INCAR}} file.
	~~{{NB\|mind\|~~This method is incompatible with the setting {{TAG\|ADDGRID}}{{=}}''.TRUE.''.}}		*The charge-density dependence of gradients is neglected.
	~~{{NB\|mind\|~~It is essential that a sufficiently dense FFT grid (controlled via {{TAG\|NGXF}}, {{TAG\|NGYF}} and {{TAG\|NGZF}} ) is used in the {{TAG\|Tkatchenko-Scheffler method}} calculation. We strongly recommend to use {{TAG\|PREC}}{{=}}''Accurate'' for this type of calculations (in any case, avoid using {{TAG\|PREC}}{{=}}''Low''}).}}		*This method is incompatible with the setting {{TAG\|ADDGRID}}{{=}}''.TRUE.''.
	~~{{NB\|mind\|~~The method sometimes has numerical problems if highly polarizable atoms are located at short distances. In such a case the calculation terminates with an error message ''Error(vdw\_tsscs\_range\_separated\_k): d\_lr(pp)<{{=}}0''. Note that this problem is not caused by a bug, but rather it is due to a limitation of the underlying physical model.}}		*It is essential that a sufficiently dense FFT grid (controlled via {{TAG\|NGXF}}, {{TAG\|NGYF}} and {{TAG\|NGZF}} ) is used in the {{TAG\|Tkatchenko-Scheffler method}} calculation. We strongly recommend to use {{TAG\|PREC}}{{=}}''Accurate'' for this type of calculations (in any case, avoid using {{TAG\|PREC}}{{=}}''Low'').
	~~{{NB\|mind\|~~Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.}}		*The method sometimes has numerical problems if highly polarizable atoms are located at short distances. In such a case the calculation terminates with an error message ''Error(vdw\_tsscs\_range\_separated\_k): d\_lr(pp)<{{=}}0''. Note that this problem is not caused by a bug, but rather it is due to a limitation of the underlying physical model.
	~~{{NB\|mind\|~~Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.}}		*Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.
	~~{{NB\|mind\|~~A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 (({{TAG\|VDW_SR}}{{=}}0.85)), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}		*Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.
			*A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 (({{TAG\|VDW_SR}}{{=}}0.85)), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}

	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|VDW_ALPHA}},		{{TAG\|VDW_ALPHA}},

← Older revision		Revision as of 20:05, 1 February 2023
Line 39:		Line 39:
	{{TAG\|LSCSGRAD}},		{{TAG\|LSCSGRAD}},
	{{TAG\|IVDW}},		{{TAG\|IVDW}},
	~~{{TAG\|IALGO}},~~
	{{TAG\|Tkatchenko-Scheffler method}},		{{TAG\|Tkatchenko-Scheffler method}},
			{{TAG\|Self-consistent screening in Tkatchenko-Scheffler method}},
	{{TAG\|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}},		{{TAG\|Tkatchenko-Scheffler method with iterative Hirshfeld partitioning}},
	{{TAG\|~~Self~~-~~consistent screening in Tkatchenko-Scheffler method~~}}		{{TAG\|Many-body dispersion energy with fractionally ionic model for polarizability}}

	== References ==		== References ==

← Older revision		Revision as of 07:50, 26 September 2023
Line 13:		Line 13:

	*{{TAG\|VDW_SR}}=0.83 : scaling parameter <math>\beta</math>		*{{TAG\|VDW_SR}}=0.83 : scaling parameter <math>\beta</math>
	*{{TAG\|LVDWEXPANSION}}=.FALSE. : writes the two- to six- body contributions to the MBD dispersion energy in the {{TAG\|OUTCAR}} ({{TAG\|LVDWEXPANSION}}=''.TRUE.'')		*{{TAG\|LVDWEXPANSION}}=.FALSE. : writes the two- to six-body contributions to the MBD dispersion energy in the {{TAG\|OUTCAR}} ({{TAG\|LVDWEXPANSION}}=''.TRUE.'')
	*{{TAG\|LSCSGRAD}}=.TRUE. : compute gradients (or not)		*{{TAG\|LSCSGRAD}}=.TRUE. : compute gradients (or not)
	*{{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, {{TAG\|VDW_R0}} : atomic reference (see ~~alse~~ {{TAG\|Tkatchenko-Scheffler method}})		*{{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}}, {{TAG\|VDW_R0}} : atomic reference (see also {{TAG\|Tkatchenko-Scheffler method}})
	*{{TAG\|ITIM}}=-1: if set to +1, apply eigenvalue remapping to avoid unphysical cases where the eigenvalues of the matrix		*{{TAG\|ITIM}}=-1: if set to +1, apply eigenvalue remapping to avoid unphysical cases where the eigenvalues of the matrix
	<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> ~~fore~~ details		<math>\left(1-\mathbf{A}^{(0)}_{LR}(\omega) {\mathbf{T}}_{LR}({\mathbf{k}})\right) </math>are non-positive, see reference<ref>[https://pubs.acs.org/doi/abs/10.1021/acs.jctc.6b00925 T. Gould, S. Lebègue, J. G. Ángyán, and T. Bučko, J. Chem. Theory Comput. 12, 5920 (2016).]</ref> for details

	~~Details of implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.~~

			Details of the implementation of the MBD@rsSCS method in VASP are presented in reference {{cite\|bucko:jpcm:16}}.
	{{NB\|mind\|This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.}}		{{NB\|mind\|This method requires the use of {{TAG\|POTCAR}} files from the PAW dataset version 52 or later.}}
	{{NB\|mind\|The input reference data for non-interacting atoms are available only for elements of the first six rows of the periodic table except of the lanthanides. If the system contains other elements, the user has to provide the free-atomic parameters for all atoms in the system via {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}} and {{TAG\|VDW_R0}} (described by the {{TAG\|Tkatchenko-Scheffler method}}) defined in the {{TAG\|INCAR}} file.}}		{{NB\|mind\|The input reference data for non-interacting atoms are available only for elements of the first six rows of the periodic table except of the lanthanides. If the system contains other elements, the user has to provide the free-atomic parameters for all atoms in the system via {{TAG\|VDW_ALPHA}}, {{TAG\|VDW_C6}} and {{TAG\|VDW_R0}} (described by the {{TAG\|Tkatchenko-Scheffler method}}) defined in the {{TAG\|INCAR}} file.}}
Line 26:		Line 25:
	{{NB\|mind\|This method is incompatible with the setting {{TAG\|ADDGRID}}{{=}}''.TRUE.''.}}		{{NB\|mind\|This method is incompatible with the setting {{TAG\|ADDGRID}}{{=}}''.TRUE.''.}}
	{{NB\|mind\|It is essential that a sufficiently dense FFT grid (controlled via {{TAG\|NGXF}}, {{TAG\|NGYF}} and {{TAG\|NGZF}} ) is used in the {{TAG\|Tkatchenko-Scheffler method}} calculation. We strongly recommend to use {{TAG\|PREC}}{{=}}''Accurate'' for this type of calculations (in any case, avoid using {{TAG\|PREC}}{{=}}''Low''}).}}		{{NB\|mind\|It is essential that a sufficiently dense FFT grid (controlled via {{TAG\|NGXF}}, {{TAG\|NGYF}} and {{TAG\|NGZF}} ) is used in the {{TAG\|Tkatchenko-Scheffler method}} calculation. We strongly recommend to use {{TAG\|PREC}}{{=}}''Accurate'' for this type of calculations (in any case, avoid using {{TAG\|PREC}}{{=}}''Low''}).}}
	{{NB\|mind\|The method has ~~sometimes~~ numerical problems if highly polarizable atoms are located at short distances. In such a case the calculation terminates with an error message ''Error(vdw\_tsscs\_range\_separated\_k): d\_lr(pp)<{{=}}0''. Note that this problem is not caused by a bug, but rather it is due to a limitation of the underlying physical model.}}		{{NB\|mind\|The method sometimes has numerical problems if highly polarizable atoms are located at short distances. In such a case the calculation terminates with an error message ''Error(vdw\_tsscs\_range\_separated\_k): d\_lr(pp)<{{=}}0''. Note that this problem is not caused by a bug, but rather it is due to a limitation of the underlying physical model.}}
	{{NB\|mind\|Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.}}		{{NB\|mind\|Analytical gradients of the energy are implemented (fore details see reference {{cite\|bucko:jpcm:16}}) and hence the atomic and lattice relaxations can be performed.}}
	{{NB\|mind\|Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.}}		{{NB\|mind\|Due to the long-range nature of dispersion interactions, the convergence of energy with respect to the number of k-points should be carefully examined.}}
	{{NB\|mind\|A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 (({{TAG\|VDW_SR}}{{=}}0.85)), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}		{{NB\|mind\|A default value for the free-parameter of this method is available only for the PBE ({{TAG\|VDW_SR}}{{=}}0.83), PBE0 ({{TAG\|VDW_SR}}{{=}}0.85), HSE06 (({{TAG\|VDW_SR}}{{=}}0.85)), B3LYP ({{TAG\|VDW_SR}}{{=}}0.64), and SCAN ({{TAG\|VDW_SR}}{{=}}1.12) functionals. If any other functional is used, the value of {{TAG\|VDW_SR}} must be specified in the {{TAG\|INCAR}} file.}}

	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|VDW_ALPHA}},		{{TAG\|VDW_ALPHA}},