Electrostatic corrections - Revision history

Kresse: /* Molecules */

2026-08-11T06:53:54Z

Molecules

← Older revision		Revision as of 06:53, 11 August 2026
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	=== Molecules ===		=== Molecules ===
	The simplest correction scheme is invoked by setting the tag {{TAG\| LMONO}}. This corrects for the interaction of a charged molecule with a homogeneous background, and the correction is prompted to the {{TAG\|OUTCAR}} file in the lines "energy correction for charged system".		The simplest correction scheme is invoked by setting the tag {{TAG\| LMONO}}. This corrects for the interaction of a charged molecule with a homogeneous background, and the correction is prompted to the {{TAG\|OUTCAR}} file in the lines "energy correction for charged system".
	This correction is roughly proportional to the reciprocal of the shortest lattice vector, and it is generally large. The tag {{TAG\|IDIPOL}}=4 (without setting {{TAG\| LMONO}}) additionally introduces corrections for interactions between repeated dipoles on the atom/molecule. Those are written to the line "dipol+quadrupol energy correction". They are proportional to the inverse volume and generally much smaller than the monopole corrections. However, the actual Kohn-Sham potential is not corrected. To correct the potential as well, add the {{TAG\|LDIPOL}} tag. Note that this can severely slow the convergence of the self-consistency loop and that the additional corrections are often small. Furthermore, this correction is only implemented for orthorhombic supercells.		This correction is roughly proportional to the reciprocal of the shortest lattice vector, and it is generally large. The tag {{TAG\|IDIPOL}}=4 (without setting {{TAG\| LMONO}}) additionally introduces corrections for interactions between repeated dipoles on the atom/molecule. Those are written to the line "dipol+quadrupol energy correction". They are proportional to the inverse volume and generally much smaller than the monopole corrections. However, the actual Kohn-Sham potential is not corrected. To correct the potential as well, add the {{TAG\|LDIPOL}} tag. Note that this can severely slow the convergence of the self-consistency loop and that the additional corrections are often small. Furthermore, this correction is only implemented for orthorhombic supercells. Similar strategies as for slabs might help to recover convergence.

	== Current limitations ==		== Current limitations ==

Kresse: /* Surfaces */

2026-08-11T06:52:33Z

Surfaces

← Older revision		Revision as of 06:52, 11 August 2026
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	The following options may be used to improve convergence for this case.		The following options may be used to improve convergence for this case.

	1. ~~Use any of these tags only after pre~~-converging the orbitals without the {{TAG\|LDIPOL}} tag		1. Pre-converging the orbitals without the {{TAG\|LDIPOL}} tag

	2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass) whenever many calculations with say different surface terminations are compared.		2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass) whenever many calculations with, say, different surface terminations are compared, or if the default algorithm fails to determine the centre of the slab/ molecules.

	3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.		3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.

Kresse at 19:49, 10 August 2026

2026-08-10T19:49:37Z

← Older revision		Revision as of 19:49, 10 August 2026
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	For charged cells or for calculations of molecules and surfaces with a large dipole moment, the energy converges very slowly with respect to the size <math>L</math> of the supercell. Using methods discussed by Makov ''et al.''<ref name="Makov95"/> and Neugebauer ''et al.''<ref name="Neugebauer92"/>, VASP can correct for the leading errors (in ~~many~~ details, ~~we have taken a~~ more general ~~approach~~, though).		For charged cells or for calculations of molecules and surfaces with a large dipole moment, the energy converges very slowly with respect to the size <math>L</math> of the supercell. Using methods discussed by Makov ''et al.''<ref name="Makov95"/> and Neugebauer ''et al.''<ref name="Neugebauer92"/>, VASP can correct for the leading errors (in some details, the VASP implementation is more general, though).

	== Suggested combination of tags for electrostatic corrections ==		== Suggested combination of tags for electrostatic corrections ==

Kresse: /* Molecules */

2026-08-10T19:01:57Z

Molecules

← Older revision		Revision as of 19:01, 10 August 2026
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	=== Molecules ===		=== Molecules ===
	The simplest correction scheme is invoked by setting the tag {{TAG\| LMONO}}. This corrects for the interaction of a charged molecule with a homogeneous background, and the correction is prompted to the {{TAG\|OUTCAR}} ~~files~~ in the lines "energy correction for charged system".		The simplest correction scheme is invoked by setting the tag {{TAG\| LMONO}}. This corrects for the interaction of a charged molecule with a homogeneous background, and the correction is prompted to the {{TAG\|OUTCAR}} file in the lines "energy correction for charged system".
	This correction is roughly proportional to the reciprocal of the shortest lattice vector, and it is generally large. The tag {{TAG\|IDIPOL}}=4 introduces corrections for interactions between repeated dipoles on the atom/molecule. Those are ~~prompted~~ to the line "dipol+quadrupol energy correction". They are proportional to the inverse volume and much smaller. However, the actual Kohn-Sham potential is not corrected. To correct the potential as well, ~~use~~ the {{TAG\|LDIPOL}} tag. Note that this can severely slow the convergence of the self-consistency loop and that the additional corrections are often small. Furthermore, this correction is only implemented for orthorhombic supercells.		This correction is roughly proportional to the reciprocal of the shortest lattice vector, and it is generally large. The tag {{TAG\|IDIPOL}}=4 (without setting {{TAG\| LMONO}}) additionally introduces corrections for interactions between repeated dipoles on the atom/molecule. Those are written to the line "dipol+quadrupol energy correction". They are proportional to the inverse volume and generally much smaller than the monopole corrections. However, the actual Kohn-Sham potential is not corrected. To correct the potential as well, add the {{TAG\|LDIPOL}} tag. Note that this can severely slow the convergence of the self-consistency loop and that the additional corrections are often small. Furthermore, this correction is only implemented for orthorhombic supercells.

	== Current limitations ==		== Current limitations ==

Kresse: /* Surfaces */

2026-08-10T15:13:40Z

Surfaces

← Older revision		Revision as of 15:13, 10 August 2026
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	If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.		If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.
	=== [[:Category:2D_materials\|Surfaces]] ===		=== [[:Category:2D_materials\|Surfaces]] ===
	If the system has a net dipole moment, the {{TAG\|IDIPOL}}=1,2,3 allows VASP to evaluate the dipole along the first, second, or third lattice vector VASP then determines an energy correction corresponding to the interaction between repeated dipoles along these vectors. The Kohn-Sham potentials are not corrected, so the potential and forces may be slightly inaccurate. To correct the potential for the spurious interactions between the dipoles, additionally set {{TAG\|LDIPOL}}=.TRUE. This can, however, slow convergence. Optionally, {{TAG\|DIPOL}} may be set to define the center of the slab.		If the system has a net dipole moment, the {{TAG\|IDIPOL}}=1,2,3 allows VASP to evaluate the dipole along the first, second, or third lattice vector. VASP then determines an energy correction corresponding to the interaction between repeated dipoles along these vectors. The Kohn-Sham potentials are not corrected, so the potential and forces may be slightly inaccurate. To correct the potential for the spurious interactions between the dipoles, additionally set {{TAG\|LDIPOL}}=.TRUE. This can, however, slow convergence. Optionally, {{TAG\|DIPOL}} may be set to define the center of the slab.

	The following options may be used to improve convergence for this case.		The following options may be used to improve convergence for this case.

Kresse: /* Surfaces */

2026-08-10T15:12:30Z

Surfaces

← Older revision		Revision as of 15:12, 10 August 2026
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	3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.		3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.
	{{NB\|warning\|Surface calculations with a net charge result in total energies that do not converge. Relative energies may still be useful.}}		{{NB\|warning\|Surface calculations with a net charge result in total energies that do not converge as the space between the slabs is increased. Relative energies may still be useful if the vacuum width is kept constant.}}

	=== Wires ===		=== Wires ===

Kresse: /* Surfaces */ Update to document hierachy of settings

2026-08-10T15:11:27Z

Surfaces: Update to document hierachy of settings

← Older revision		Revision as of 15:11, 10 August 2026
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	If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.		If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.
	=== [[:Category:2D_materials\|Surfaces]] ===		=== [[:Category:2D_materials\|Surfaces]] ===
	If the system has a net dipole moment, ~~a combination of~~ {{TAG\|IDIPOL}}=1,2,3 and {{TAG\|LDIPOL}} ~~tags may be used~~. ~~The former corrects the energies~~, ~~while the latter corrects the potential and forces~~. Optionally, {{TAG\|DIPOL}} may be set. The following options may be used to improve convergence for this case.		If the system has a net dipole moment, the {{TAG\|IDIPOL}}=1,2,3 allows VASP to evaluate the dipole along the first, second, or third lattice vector VASP then determines an energy correction corresponding to the interaction between repeated dipoles along these vectors. The Kohn-Sham potentials are not corrected, so the potential and forces may be slightly inaccurate. To correct the potential for the spurious interactions between the dipoles, additionally set {{TAG\|LDIPOL}}=.TRUE. This can, however, slow convergence. Optionally, {{TAG\|DIPOL}} may be set to define the center of the slab.

			The following options may be used to improve convergence for this case.

	1. Use any of these tags only after pre-converging the orbitals without the {{TAG\|LDIPOL}} tag		1. Use any of these tags only after pre-converging the orbitals without the {{TAG\|LDIPOL}} tag

	2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass)		2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass) whenever many calculations with say different surface terminations are compared.

	3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.		3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.

Kresse: /* Molecules */ more careful rewrite

2026-08-10T15:00:56Z

Molecules: more careful rewrite

← Older revision		Revision as of 15:00, 10 August 2026
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	=== Molecules ===		=== Molecules ===
	The simplest correction scheme is invoked by setting the tag {{TAG\| LMONO}}. This corrects for the interaction of a charged molecule with a homogeneous background and is ~~promted~~ to the {{TAG\|OUTCAR}} files ~~along~~ the lines (energy correction for charged system).		The simplest correction scheme is invoked by setting the tag {{TAG\| LMONO}}. This corrects for the interaction of a charged molecule with a homogeneous background, and the correction is prompted to the {{TAG\|OUTCAR}} files in the lines "energy correction for charged system".
	~~The corresponding~~ correction is roughly proportional to the reciprocal of the shortest lattice vector. ~~Adding the~~ tag {{TAG\|IDIPOL}}=4 ~~also~~ introduces corrections for interactions between repeated dipoles on the atom/molecule. However, the actual Kohn-Sham potential is not corrected. To correct the potential as well, use the {{TAG\|LDIPOL}} tag. Note that this can severely slow the convergence of the self-consistency loop and that the additional corrections are often small.		This correction is roughly proportional to the reciprocal of the shortest lattice vector, and it is generally large. The tag {{TAG\|IDIPOL}}=4 introduces corrections for interactions between repeated dipoles on the atom/molecule. Those are prompted to the line "dipol+quadrupol energy correction". They are proportional to the inverse volume and much smaller. However, the actual Kohn-Sham potential is not corrected. To correct the potential as well, use the {{TAG\|LDIPOL}} tag. Note that this can severely slow the convergence of the self-consistency loop and that the additional corrections are often small. Furthermore, this correction is only implemented for orthorhombic supercells.

	== Current limitations ==		== Current limitations ==

Kresse: /* Molecules */ updated to explain LMONO, IDIPOL=4, LDIPOL hierachie

2026-08-10T14:37:28Z

Molecules: updated to explain LMONO, IDIPOL=4, LDIPOL hierachie

← Older revision		Revision as of 14:37, 10 August 2026
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	=== Molecules ===		=== Molecules ===
	If the ~~system has~~ a ~~net dipole moment, use~~ the {{TAG\|~~LDIPOL~~}} ~~tag~~. The ~~former corrects~~ the ~~energies~~, ~~while~~ the ~~latter corrects~~ the potential ~~and forces. Optionally~~, {{TAG\|~~DIPOL~~}} ~~may be set~~.		The simplest correction scheme is invoked by setting the tag {{TAG\| LMONO}}. This corrects for the interaction of a charged molecule with a homogeneous background and is promted to the {{TAG\|OUTCAR}} files along the lines (energy correction for charged system).
			The corresponding correction is roughly proportional to the reciprocal of the shortest lattice vector. Adding the tag {{TAG\|IDIPOL}}=4 also introduces corrections for interactions between repeated dipoles on the atom/molecule. However, the actual Kohn-Sham potential is not corrected. To correct the potential as well, use the {{TAG\|LDIPOL}} tag. Note that this can severely slow the convergence of the self-consistency loop and that the additional corrections are often small.

	== Current limitations ==		== Current limitations ==

Kresse: Grammar correction

2026-03-17T07:23:09Z

Grammar correction

← Older revision		Revision as of 07:23, 17 March 2026
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	== Suggested combination of tags for electrostatic corrections ==		== Suggested combination of tags for electrostatic corrections ==
	In cases where the system has no net charge and no net dipole moment, no specific tags need to be set and this section can be skipped.		In cases where the system has no net charge and no net dipole moment, no specific tags need to be set, and this section can be skipped.
	=== Bulk ===		=== Bulk ===
	If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.		If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.
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	2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass)		2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass)

	3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might ~~slash through~~ the vacuum, causing very slow convergence. Often convergence improves with the ~~size of the supercell~~.		3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.
	{{NB\|warning\|Surface calculations with a net charge result in total energies that do not converge. Relative energies may still be useful.}}		{{NB\|warning\|Surface calculations with a net charge result in total energies that do not converge. Relative energies may still be useful.}}

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	In this section, we discuss step-by-step instructions to use the dipole corrections for slab calculations.		In this section, we discuss step-by-step instructions to use the dipole corrections for slab calculations.

	'''Step 1:''' Create a system ~~which~~ has enough vacuum on either side of the surface normal. An example for such a structure is shown below, for an fcc-Aluminium with a carbon adsorbed on one of its surface terminations.		'''Step 1:''' Create a system that has enough vacuum on either side of the surface normal. An example for such a structure is shown below, for an fcc-Aluminium with a carbon adsorbed on one of its surface terminations.
	Al3C		Al3C
	1.0000000000000000		1.0000000000000000
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	Note that the system has plenty of vacuum on either side. This empty space is important for the potential corrections needed for the {{TAG\|LDIPOL}} tag.		Note that the system has plenty of vacuum on either side. This empty space is important for the potential corrections needed for the {{TAG\|LDIPOL}} tag.

	'''Step 2:''' Switch on the dipole corrections to the energy, potential and forces. Optionally set the {{TAG\|DIPOL}}		'''Step 2:''' Switch on the dipole corrections to the energy, potential, and forces. Optionally set the {{TAG\|DIPOL}}

	LDIPOL = T		LDIPOL = T

← Older revision		Revision as of 15:11, 10 August 2026
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	If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.		If the system has a net dipole or net charge, please follow the recommendations of [[Dipole_corrections_for_defects_in_solids\|this]] wiki page.
	=== [[:Category:2D_materials\|Surfaces]] ===		=== [[:Category:2D_materials\|Surfaces]] ===
	If the system has a net dipole moment, ~~a combination of~~ {{TAG\|IDIPOL}}=1,2,3 and {{TAG\|LDIPOL}} ~~tags may be used~~. ~~The former corrects the energies~~, ~~while the latter corrects the potential and forces~~. Optionally, {{TAG\|DIPOL}} may be set. The following options may be used to improve convergence for this case.		If the system has a net dipole moment, the {{TAG\|IDIPOL}}=1,2,3 allows VASP to evaluate the dipole along the first, second, or third lattice vector VASP then determines an energy correction corresponding to the interaction between repeated dipoles along these vectors. The Kohn-Sham potentials are not corrected, so the potential and forces may be slightly inaccurate. To correct the potential for the spurious interactions between the dipoles, additionally set {{TAG\|LDIPOL}}=.TRUE. This can, however, slow convergence. Optionally, {{TAG\|DIPOL}} may be set to define the center of the slab.

			The following options may be used to improve convergence for this case.

	1. Use any of these tags only after pre-converging the orbitals without the {{TAG\|LDIPOL}} tag		1. Use any of these tags only after pre-converging the orbitals without the {{TAG\|LDIPOL}} tag

	2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass)		2. The center of charge should be set in the {{FILE\|INCAR}} file ({{TAG\|DIPOL}}= center of mass) whenever many calculations with say different surface terminations are compared.

	3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.		3. Ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy (see {{TAG\|DIPOL}}). If the cell is too small, the charge might slosh into the vacuum, causing very slow convergence. Often, convergence improves with the vacuum width.