DIPOL - Revision history

Huebsch at 12:28, 23 October 2025

2025-10-23T12:28:09Z

← Older revision		Revision as of 12:28, 23 October 2025
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	----		----

	[[Category:INCAR tag]][[Category:Molecules]][[Category:~~Monopole Dipole and Quadrupole Corrections~~]]		[[Category:INCAR tag]][[Category:Molecules]][[Category:Electrostatics]]

Hampel at 10:22, 17 February 2025

2025-02-17T10:22:50Z

← Older revision		Revision as of 10:22, 17 February 2025
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	</math>		</math>
	This measure will provide consistent values only if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is		This measure will provide consistent values only if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is
	not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>. In such cases, it might be beneficial to increase the size of the cell along the vacuum dimension (for surfaces) or for the entire cell (for isolated molecules). For practical purposes this means that for slab calculations or surfaces the position specified by {{TAG\|DIPOL}} should roughly correspond to the center of mass of the atoms in the cell, so that there is enough vacuum for the field to dissipate.		not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>. In such cases, it might be beneficial to increase the size of the cell along the vacuum dimension (for surfaces) or for the entire cell (for isolated molecules). For practical purposes this means that for slab calculations or surfaces the position specified by {{TAG\|DIPOL}} should roughly correspond to the center of mass of the atoms in the cell, so that there is enough vacuum for the field to dissipate. See the [[Electrostatic_corrections\|Electrostatic corrections]] page for an example.

	{{NB\|mind\| If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells)}}		{{NB\|mind\| If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells)}}

Hampel: /* Related tags and articles */

2025-02-17T10:17:30Z

Hampel at 09:54, 17 February 2025

2025-02-17T09:54:20Z

← Older revision		Revision as of 09:54, 17 February 2025
Line 14:		Line 14:
	</math>		</math>
	This measure will provide consistent values only if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is		This measure will provide consistent values only if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is
	not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>. In such cases, it might be beneficial to increase the size of the cell along the vacuum dimension (for surfaces) or for the entire cell (for isolated molecules).		not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>. In such cases, it might be beneficial to increase the size of the cell along the vacuum dimension (for surfaces) or for the entire cell (for isolated molecules). For practical purposes this means that for slab calculations or surfaces the position specified by {{TAG\|DIPOL}} should roughly correspond to the center of mass of the atoms in the cell, so that there is enough vacuum for the field to dissipate.

	{{NB\|mind\| If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells)}}		{{NB\|mind\| If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells)}}
	{{NB\|tip\| For calculations of isolated molecules and surfaces with the dipole correction, use {{TAG\|DIPOL}} as the center of mass of the atoms in your cell. Additionally, note that for surfaces, only the component normal to the surface is meaningful.}}		{{NB\|tip\| For calculations of isolated molecules and surfaces with the dipole correction, use {{TAG\|DIPOL}} as the center of mass of the atoms in your cell. Additionally, note that for surfaces, only the component normal to the surface is meaningful.}}

Svijay at 12:08, 18 October 2023

2023-10-18T12:08:14Z

← Older revision		Revision as of 12:08, 18 October 2023
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	where '''R'''<sub>x</sub>, '''R'''<sub>y</sub> and '''R'''<sub>z</sub> are given in direct lattice coordinates.		where '''R'''<sub>x</sub>, '''R'''<sub>y</sub> and '''R'''<sub>z</sub> are given in direct lattice coordinates.

	Calculations using the dipole correction, i.e. using tags {{TAG\|IDIPOL}} or {{TAG\|LDIPOL}} require a definition of the center of the cell. Results of the computed dipole moment might differ for different positions. The reason for this difference is that the definition of the dipole 'destroys' the translational symmetry, i.e., the dipole is defined as		Calculations using the dipole correction, i.e. using tags {{TAG\|IDIPOL}} or {{TAG\|LDIPOL}}, require a definition of the center of the cell. Results of the computed dipole moment might differ for different positions. The reason for this difference is that the definition of the dipole 'destroys' the translational symmetry, i.e., the dipole is defined as
	:<math>		:<math>
	\int ({\mathbf r}-{\mathbf R}_{\rm center}) \rho_{\rm ions+valence}({\mathbf r}) d^3 {\mathbf r}.		\int ({\mathbf r}-{\mathbf R}_{\rm center}) \rho_{\rm ions+valence}({\mathbf r}) d^3 {\mathbf r}.

Svijay at 12:07, 18 October 2023

2023-10-18T12:07:39Z

← Older revision		Revision as of 12:07, 18 October 2023
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	where '''R'''<sub>x</sub>, '''R'''<sub>y</sub> and '''R'''<sub>z</sub> are given in direct lattice coordinates.		where '''R'''<sub>x</sub>, '''R'''<sub>y</sub> and '''R'''<sub>z</sub> are given in direct lattice coordinates.

	~~'''Mind''': the calculation of~~ the dipole ({{TAG\|IDIPOL}}~~=1-4) requires~~ a definition of the center of the cell~~, and results~~ might differ for different positions.		Calculations using the dipole correction, i.e. using tags {{TAG\|IDIPOL}} or {{TAG\|LDIPOL}} require a definition of the center of the cell. Results of the computed dipole moment might differ for different positions. The reason for this difference is that the definition of the dipole 'destroys' the translational symmetry, i.e., the dipole is defined as
	~~You should use this option only~~ for ~~surfaces and isolated molecules.~~
	In this ~~case, use the center of mass for the position. Additionally, mind that for surfaces, only the component normal to the surface is meaningful.~~

	~~The main problem~~ is that the definition of the dipole 'destroys' the translational symmetry, i.e., the dipole is defined as

	:<math>		:<math>
	\int ({\mathbf r}-{\mathbf R}_{\rm center}) \rho_{\rm ions+valence}({\mathbf r}) d^3 {\mathbf r}.		\int ({\mathbf r}-{\mathbf R}_{\rm center}) \rho_{\rm ions+valence}({\mathbf r}) d^3 {\mathbf r}.
	</math>		</math>
			This measure will provide consistent values only if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is
	~~Now, this makes~~ only ~~sense~~ if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is		not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>. In such cases, it might be beneficial to increase the size of the cell along the vacuum dimension (for surfaces) or for the entire cell (for isolated molecules).
	not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>.
	{{NB\|mind\| If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells)}}		{{NB\|mind\| If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells)}}
			{{NB\|tip\| For calculations of isolated molecules and surfaces with the dipole correction, use {{TAG\|DIPOL}} as the center of mass of the atoms in your cell. Additionally, note that for surfaces, only the component normal to the surface is meaningful.}}

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

Svijay at 15:25, 17 October 2023

2023-10-17T15:25:55Z

← Older revision		Revision as of 15:25, 17 October 2023
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	Now, this makes only sense if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is		Now, this makes only sense if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is
	not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>.		not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>.
			{{NB\|mind\| If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells)}}

	'''Note''': If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells).

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

Karsai at 14:10, 8 April 2022

2022-04-08T14:10:36Z

← Older revision		Revision as of 14:10, 8 April 2022
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	'''Note''': If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells).		'''Note''': If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells).

	== Related ~~Tags~~ and ~~Sections~~ ==		== Related tags and articles ==
	{{TAG\|NELECT}},		{{TAG\|NELECT}},
	{{TAG\|EPSILON}},		{{TAG\|EPSILON}},
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	{{sc\|DIPOL\|Examples\|Examples that use this tag}}		{{sc\|DIPOL\|Examples\|Examples that use this tag}}
	----		----
	~~[[The_VASP_Manual\|Contents]]~~

	[[Category:INCAR]][[Category:Molecules]][[Category:Monopole Dipole and Quadrupole Corrections]]		[[Category:INCAR tag]][[Category:Molecules]][[Category:Monopole Dipole and Quadrupole Corrections]]

Huebsch at 05:39, 10 August 2021

2021-08-10T05:39:30Z

← Older revision		Revision as of 05:39, 10 August 2021
Line 11:		Line 11:
	'''Mind''': the calculation of the dipole ({{TAG\|IDIPOL}}=1-4) requires a definition of the center of the cell, and results might differ for different positions.		'''Mind''': the calculation of the dipole ({{TAG\|IDIPOL}}=1-4) requires a definition of the center of the cell, and results might differ for different positions.
	You should use this option only for surfaces and isolated molecules.		You should use this option only for surfaces and isolated molecules.
	In this case use the center of mass for the position (for ~~surface~~ only the component normal to the surface is meaningful).		In this case, use the center of mass for the position. Additionally, mind that for surfaces, only the component normal to the surface is meaningful.

	The main problem is that the definition of the dipole 'destroys' the translational symmetry, i.e. the dipole is defined as		The main problem is that the definition of the dipole 'destroys' the translational symmetry, i.e., the dipole is defined as

	:<math>		:<math>
Line 20:		Line 20:

	Now, this makes only sense if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is		Now, this makes only sense if <math>\rho_{\rm ions+valence}</math> drops to zero at some distance from <math>\mathbf R_{\rm center}</math>. If this is
	not the case, the values are extremely ~~sensible~~ with respect to changes in <math>\mathbf R_{\rm center}</math>.		not the case, the values are extremely sensitive with respect to changes in <math>\mathbf R_{\rm center}</math>.

	'''Note''': If the flag is not set, VASP determines, where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells).		'''Note''': If the flag is not set, VASP determines where the charge density averaged over one plane drops to a minimum and calculates the center of the charge distribution by adding half of the lattice vector perpendicular to the plane where the charge density has a minimum (this is a rather reliable approach for orthorhombic cells).

	== Related Tags and Sections ==		== Related Tags and Sections ==

Karsai at 16:27, 16 April 2019

2019-04-16T16:27:52Z

← Older revision		Revision as of 16:27, 16 April 2019
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	[[The_VASP_Manual\|Contents]]		[[The_VASP_Manual\|Contents]]

	[[Category:INCAR]][[Category:Molecules]]		[[Category:INCAR]][[Category:Molecules]][[Category:Monopole Dipole and Quadrupole Corrections]]

← Older revision		Revision as of 10:17, 17 February 2025
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	{{TAG\|LMONO}},		{{TAG\|LMONO}},
	{{TAG\|EFIELD}},		{{TAG\|EFIELD}},
	[[Monopole_Dipole_and_Quadrupole_corrections\|Monopole, Dipole and Quadrupole corrections]]		[[Monopole_Dipole_and_Quadrupole_corrections\|Monopole, Dipole and Quadrupole corrections]],
			[[Electrostatic_corrections\|Electrostatic corrections]]

	{{sc\|DIPOL\|Examples\|Examples that use this tag}}		{{sc\|DIPOL\|Examples\|Examples that use this tag}}