Choosing pseudopotentials - Revision history

Wolloch: /* Recommendations and advice */

2026-03-17T11:19:37Z

Recommendations and advice

← Older revision		Revision as of 11:19, 17 March 2026
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	{{NB\|tip\|For compatibility reasons or to accurately reproduce another calculation, you might need to use another (older) pseudopotential release. Consult the list of [[available pseudopotentials]].\|:}}		{{NB\|tip\|For compatibility reasons or to accurately reproduce another calculation, you might need to use another (older) pseudopotential release. Consult the list of [[available pseudopotentials]].\|:}}

	===Hydrogen-like atoms with fractional valence===		===Element-specific recommendation===

			====Hydrogen-like atoms with fractional valence====
	:Twelve hydrogen-like potentials are supplied for a valency between 0.25 and 1.75. Further potentials might become available, c.f. [[available pseudopotentials]]. These are useful, e.g., to passivate dangling surface bonds.		:Twelve hydrogen-like potentials are supplied for a valency between 0.25 and 1.75. Further potentials might become available, c.f. [[available pseudopotentials]]. These are useful, e.g., to passivate dangling surface bonds.
	{{NB\|mind\|The {{FILE\|POTCAR}} files restrict the number of digits for the valency (typically 2, at most 3 digits). Therefor, using three H.33 potentials does yield 0.99 electrons and not 1.00 electron. This can cause undesirable hole- or electron-like states. Set the {{TAG\|NELECT}} tag in the {{FILE\|INCAR}} file to correct the total number of electrons.\|:}}		{{NB\|mind\|The {{FILE\|POTCAR}} files restrict the number of digits for the valency (typically 2, at most 3 digits). Therefor, using three H.33 potentials does yield 0.99 electrons and not 1.00 electron. This can cause undesirable hole- or electron-like states. Set the {{TAG\|NELECT}} tag in the {{FILE\|INCAR}} file to correct the total number of electrons.\|:}}

	===First-row elements===		====First-row elements====

	:For the 1st row elements B, C, N, O, and F, three potential versions exist, the plain one, a hard version, and a soft version. For most purposes, the standard version of PAW potentials is most appropriate. They yield reliable results for energy cutoffs between 325 and 400 eV, where 370-400 eV are required to predict vibrational properties accurately. Binding geometries and energy differences are already well reproduced at 325 eV. The typical bond-length errors for first row dimers (N<sub>2</sub>, CO, O<sub>2</sub>) are about 1% compared to more accurate DFT calculations. The [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|hard pseudopotentials (_h)]] give results that are essentially identical to the best DFT calculations presently available (FLAPW, or Gaussian with very large basis sets). The [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|soft potentials (_s)]] are optimized to work around 250-280 eV. They yield reliable description for most oxides, such as V<sub>x</sub>O<sub>y</sub>, TiO<sub>2</sub>, CeO<sub>2</sub>, but fail to describe some structural details in zeolites, i.e., cell parameters, and volume.		:For the 1st row elements B, C, N, O, and F, three potential versions exist, the plain one, a hard version, and a soft version. For most purposes, the standard version of PAW potentials is most appropriate. They yield reliable results for energy cutoffs between 325 and 400 eV, where 370-400 eV are required to predict vibrational properties accurately. Binding geometries and energy differences are already well reproduced at 325 eV. The typical bond-length errors for first row dimers (N<sub>2</sub>, CO, O<sub>2</sub>) are about 1% compared to more accurate DFT calculations. The [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|hard pseudopotentials (_h)]] give results that are essentially identical to the best DFT calculations presently available (FLAPW, or Gaussian with very large basis sets). The [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|soft potentials (_s)]] are optimized to work around 250-280 eV. They yield reliable description for most oxides, such as V<sub>x</sub>O<sub>y</sub>, TiO<sub>2</sub>, CeO<sub>2</sub>, but fail to describe some structural details in zeolites, i.e., cell parameters, and volume.
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	{{NB\|tip\|If dimers with short bonds are present in the system (H<sub>2</sub>O, O<sub>2</sub>, CO, N<sub>2</sub>, F<sub>2</sub>, P<sub>2</sub>, S<sub>2</sub>, Cl<sub>2</sub>), we recommend using the _h potentials. Specifically, C_h, O_h, N_h, F_h, P_h, S_h, Cl_h, or their _GW counterparts. Otherwise, the standard version is often the best choice for first-row elements.\|:}}		{{NB\|tip\|If dimers with short bonds are present in the system (H<sub>2</sub>O, O<sub>2</sub>, CO, N<sub>2</sub>, F<sub>2</sub>, P<sub>2</sub>, S<sub>2</sub>, Cl<sub>2</sub>), we recommend using the _h potentials. Specifically, C_h, O_h, N_h, F_h, P_h, S_h, Cl_h, or their _GW counterparts. Otherwise, the standard version is often the best choice for first-row elements.\|:}}

	===Alkali and alkali-earth elements (simple metals)===		====Alkali and alkali-earth elements (simple metals)====
	:For Li (and Be), a standard potential and a potential that treats the 1<i>s</i> shell as valence states are available (Li_sv, Be_sv). One should use the _sv potentials for many applications since their transferability is much higher than the standard potentials.		:For Li (and Be), a standard potential and a potential that treats the 1<i>s</i> shell as valence states are available (Li_sv, Be_sv). One should use the _sv potentials for many applications since their transferability is much higher than the standard potentials.

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	{{NB\|tip\|For alkali and alkali-earth metals, the _sv variants should be chosen, other than for very light elements Na, Mg, K, and Ca, where _pv is usually sufficient.\|:}}		{{NB\|tip\|For alkali and alkali-earth metals, the _sv variants should be chosen, other than for very light elements Na, Mg, K, and Ca, where _pv is usually sufficient.\|:}}

	===p-elements===		====p-elements====
	:For Ga, Ge, In, Sn, Tl-At, the lower-lying <i>d</i> states should be treated as valence states (_d potential). For these elements, alternative potentials that treat the <i>d</i> states as core states are also available but should be used with great care.		:For Ga, Ge, In, Sn, Tl-At, the lower-lying <i>d</i> states should be treated as valence states (_d potential). For these elements, alternative potentials that treat the <i>d</i> states as core states are also available but should be used with great care.

	===d-elements===		====d-elements====
	:For the <i>d</i> elements, applies the same as for the alkali and earth-alkali metals: the semi-core <i>p</i> states and possibly the semi-core <i>s</i> states should be treated as valence states. In most cases, however, reliable results can be obtained even if the semi-core states are kept frozen.		:For the <i>d</i> elements, applies the same as for the alkali and earth-alkali metals: the semi-core <i>p</i> states and possibly the semi-core <i>s</i> states should be treated as valence states. In most cases, however, reliable results can be obtained even if the semi-core states are kept frozen.

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	{{NB\|tip\|As a rule of thumb the <i>p</i> states should be treated as valence states for d-elements, if their eigenenergy <math>\epsilon</math> lies above 3 Ry.\|:}}		{{NB\|tip\|As a rule of thumb the <i>p</i> states should be treated as valence states for d-elements, if their eigenenergy <math>\epsilon</math> lies above 3 Ry.\|:}}

	===f-elements===		====f-elements====

	:Due to self-interaction errors, <i>f</i> electrons are not handled well by the presently available density functionals. In particular, partially filled <i>f</i> states are often incorrectly described. For instance, all <i>f</i> states are pinned at the Fermi-level, leading to large overbinding for Pr-Eu and Tb-Yb. The errors are largest at quarter and three-quarter filling, e.g., Gd is handled reasonably well since 7 electrons occupy the majority <i>f</i> shell. These errors are DFT and not VASP related.		:Due to self-interaction errors, <i>f</i> electrons are not handled well by the presently available density functionals. In particular, partially filled <i>f</i> states are often incorrectly described. For instance, all <i>f</i> states are pinned at the Fermi-level, leading to large overbinding for Pr-Eu and Tb-Yb. The errors are largest at quarter and three-quarter filling, e.g., Gd is handled reasonably well since 7 electrons occupy the majority <i>f</i> shell. These errors are DFT and not VASP related.
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	:For some elements, [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|soft versions (_s)]] are available as well. The semi-core <i>p</i> states are always treated as valence states, whereas the semi-core <i>s</i> states are treated as valence states only in the standard potentials. For most applications (oxides, sulfides), the standard version should be used since the soft versions might result in <i>s</i> ghost-states close to the Fermi-level (,e.g., Ce_s in ceria). The soft versions are, however, expected to be sufficiently accurate for calculations on intermetallic compounds.		:For some elements, [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|soft versions (_s)]] are available as well. The semi-core <i>p</i> states are always treated as valence states, whereas the semi-core <i>s</i> states are treated as valence states only in the standard potentials. For most applications (oxides, sulfides), the standard version should be used since the soft versions might result in <i>s</i> ghost-states close to the Fermi-level (,e.g., Ce_s in ceria). The soft versions are, however, expected to be sufficiently accurate for calculations on intermetallic compounds.

	====Lanthanides with fixed valence====		=====Lanthanides with fixed valence=====

	:In addition, special GGA potentials are supplied for Ce-Lu, in which <i>f</i> electrons are kept frozen in the core, which is an attempt to treat the localized nature of <i>f</i> electrons. The number of f electrons in the core equals the total number of valence electrons minus the formal valency. For instance, according to the periodic table, Sm has a total of 8 valence electrons, i.e., 6 <i>f</i> electrons and 2 <i>s</i> electrons. In most compounds, Sm adopts a valency of 3; hence 5 <i>f</i> electrons are placed in the core when the pseudopotential is generated. The corresponding potential can be found in the directory Sm_3. The formal valency n is indicted by _n, where n is either 3 or 2. Ce_3 is, for instance, a Ce potential for trivalent Ce (for tetravalent Ce, the standard potential should be used).		:In addition, special GGA potentials are supplied for Ce-Lu, in which <i>f</i> electrons are kept frozen in the core, which is an attempt to treat the localized nature of <i>f</i> electrons. The number of f electrons in the core equals the total number of valence electrons minus the formal valency. For instance, according to the periodic table, Sm has a total of 8 valence electrons, i.e., 6 <i>f</i> electrons and 2 <i>s</i> electrons. In most compounds, Sm adopts a valency of 3; hence 5 <i>f</i> electrons are placed in the core when the pseudopotential is generated. The corresponding potential can be found in the directory Sm_3. The formal valency n is indicted by _n, where n is either 3 or 2. Ce_3 is, for instance, a Ce potential for trivalent Ce (for tetravalent Ce, the standard potential should be used).
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	{{NB\|tip\|If you are not interested in 4<i>f</i>-magnetism, and know the valency of your lanthanide, use the _2 or _3 potentials.\|:}}		{{NB\|tip\|If you are not interested in 4<i>f</i>-magnetism, and know the valency of your lanthanide, use the _2 or _3 potentials.\|:}}

	~~===Test your setup===~~
	:Even if you have taken a lot of care to optimize your pseudopotential choice, it is always good to perform some test calculations with other potentials, if necessary on a small prototype system. You might realize that you need extra accuracy, or that you are leaving performance on the table by using unnecessarily hard {{FILE\|POTCAR}}s for your problem.

	===Example: NiO equilibrium volume===		{{NB\|important\|Even if you have taken a lot of care to optimize your pseudopotential choice, it is always good to perform some test calculations with other potentials, if necessary, on a small prototype system. You might realize that you need extra accuracy, or that you are leaving performance on the table by using unnecessarily hard {{FILE\|POTCAR}}s for your problem.}}

			==Example: NiO equilibrium volume==

	Antiferromagnetic NiO in the rocksalt structure is a prototype system for a correlated material. It is a Mott insulator and not well described with standard DFT. To get correct material properties, methods beyond DFT are required. [[DFT+DMFT calculations]] are an option, but the much cheaper [[DFT+U]] approach is often used with satisfactory results.		Antiferromagnetic NiO in the rocksalt structure is a prototype system for a correlated material. It is a Mott insulator and not well described with standard DFT. To get correct material properties, methods beyond DFT are required. [[DFT+DMFT calculations]] are an option, but the much cheaper [[DFT+U]] approach is often used with satisfactory results.

Wolloch: /* Selecting a pseudopotential set */

2026-03-17T11:11:35Z

Selecting a pseudopotential set

← Older revision		Revision as of 11:11, 17 March 2026
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	\|}		\|}

	===Selecting ~~a pseudopotential set~~===		===Selecting the release version===
	:Generally, we recommend using the latest release of pseudopotentials.		:Generally, we recommend using the latest release of pseudopotentials.
	{{NB\|tip\|For compatibility reasons or to accurately reproduce another calculation, you might need to use another (older) pseudopotential release. Consult the list of [[available pseudopotentials]].\|:}}		{{NB\|tip\|For compatibility reasons or to accurately reproduce another calculation, you might need to use another (older) pseudopotential release. Consult the list of [[available pseudopotentials]].\|:}}

Wolloch at 10:16, 24 October 2025

2025-10-24T10:16:22Z

Show changes

Huebsch: /* Aspects to refine the choice of pseudopotentials */

2024-06-26T11:57:01Z

Aspects to refine the choice of pseudopotentials

← Older revision		Revision as of 11:57, 26 June 2024
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	==Aspects to refine the choice of pseudopotentials==		==Aspects to refine the choice of pseudopotentials==

	'''Aspect 1:''' ~~Analyze the geometry of your structure for short bonds~~ and the valency of the ions.		'''Aspect 1:''' The bond lengths and the valency of the ions.

	:Short bonds will require harder potentials, and semicore states might have to be treated as valence for certain chemical bonding. For some elements, variants for specific valency exist; for example, the suffix [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_2 or _3]] can be used to describe [[#Lanthanides with fixed valence\| fixed divalent or trivalent Lanthanides]].		:Short bonds will require harder potentials, and semicore states might have to be treated as valence for certain chemical bonding. For some elements, variants for specific valency exist; for example, the suffix [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_2 or _3]] can be used to describe [[#Lanthanides with fixed valence\| fixed divalent or trivalent Lanthanides]].

	'''Aspect 2:''' ~~Consider the~~ physical or chemical property ~~that is the objective~~ of ~~your calculation~~.		'''Aspect 2:''' The physical or chemical property of interest.

	:If you are only interested in a rough [[Ionic minimization\|structure optimization]], soft potentials ([[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_s]]) with minimal valency may suffice. This approach might also work for [[Phonons\|phonon calculations]] that rely on large supercells.		:If you are only interested in a rough [[Ionic minimization\|structure optimization]], soft potentials ([[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_s]]) with minimal valency may suffice. This approach might also work for [[Phonons\|phonon calculations]] that rely on large supercells.
	:On the other hand, when optimizing a magnetic structure, it may be necessary to include semicore states in the valence ([[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_pv and _sv]]).		:On the other hand, when optimizing a magnetic structure, it may be necessary to include semicore states in the valence ([[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_pv and _sv]]).
	:For the computation of [[optical properties]], it is crucial to use [[Available pseudopotentials#GW potentials\|GW potentials]].		:For the computation of [[optical properties]], it is crucial to use [[Available pseudopotentials#GW potentials\|GW potentials]].

	'''Aspect 3:''' ~~Scrutinize the requirements of the~~ method or algorithm used in your calculation.		'''Aspect 3:''' The method or algorithm used in your calculation.

	:For any calculation involving unoccupied states significantly above the Fermi energy, the [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_GW variants]] of potentials are superior and should be used. Particularly, all kinds of [[Many-body perturbation theory\|calculations within many-body perturbation theory]] need a high number of [[NBANDS#Many-body_perturbation_theory_calculations\|empty bands]]. Therefore, when GW, BSE, etc. is performed, the [[Available pseudopotentials#GW potentials\|GW potentials]] should be used throughout the workflow.		:For any calculation involving unoccupied states significantly above the Fermi energy, the [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_GW variants]] of potentials are superior and should be used. Particularly, all kinds of [[Many-body perturbation theory\|calculations within many-body perturbation theory]] need a high number of [[NBANDS#Many-body_perturbation_theory_calculations\|empty bands]]. Therefore, when GW, BSE, etc. is performed, the [[Available pseudopotentials#GW potentials\|GW potentials]] should be used throughout the workflow.

Huebsch: /* Related tags and sections */

2024-06-20T06:15:39Z

Related tags and sections

← Older revision		Revision as of 06:15, 20 June 2024
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	{{FILE\|POTCAR}}, [[Prepare a POTCAR]], [[Available pseudopotentials]]		{{FILE\|POTCAR}}, [[Prepare a POTCAR]], [[Available pseudopotentials]]

	Theoretical background: [[Pseudopotentials~~]], [[Pseudopotential basics~~]], [[Projector-augmented-wave formalism]]		Theoretical background: [[Pseudopotentials]], [[Projector-augmented-wave formalism]]

			==References==

	[[Category:Pseudopotentials]][[Category:Howto]]		[[Category:Pseudopotentials]][[Category:Howto]]

Wolloch: /* Recommendations and advice */

2024-06-13T09:41:08Z

Recommendations and advice

← Older revision		Revision as of 09:41, 13 June 2024
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	:The following table highlights recommended PAW potentials for calculations involving many states above the Fermi energy in '''bold'''.		:The following table highlights recommended PAW potentials for calculations involving many states above the Fermi energy in '''bold'''.
	:They are optimized for scattering properties high above the Fermi level and thus have advantages if many unoccupied states are involved, as for [[optical properties]] or [[many-body perturbation theory]]. Some results indicate that these GW potentials are also more accurate for ground-state-DFT calculations{{cite\|bosoni:natphysrev:2023}}, but the results should be very comparable with the standard potentials in most cases. Unless the uttermost accuracy is required, it is usually not worth paying the extra computational cost required<ref>For the potpaw_PBE.64 potential set, {{TAG\|ENMAX}} is on average ~26 eV (~11%) and {{TAG\|EAUG}} ~210 eV (42%) larger for the GW potentials compared to their standard counterparts with the same valency.</ref> for the GW potentials compared to their standard counterparts.		:They are optimized for scattering properties high above the Fermi level and thus have advantages if many unoccupied states are involved, as for [[optical properties]] or [[many-body perturbation theory]]. Some results indicate that these GW potentials are also more accurate for ground-state-DFT calculations{{cite\|bosoni:natphysrev:2023}}, but the results should be very comparable with the standard potentials in most cases. Unless the uttermost accuracy is required, it is usually not worth paying the extra computational cost required<ref>For the potpaw_PBE.64 potential set, {{TAG\|ENMAX}} is on average ~26 eV (~11%) and {{TAG\|EAUG}} ~210 eV (~42%) larger for the GW potentials compared to their standard counterparts with the same valency.</ref> for the GW potentials compared to their standard counterparts.

	:{\| class="wikitable sortable mw-collapsible mw-collapsed"		:{\| class="wikitable sortable mw-collapsible mw-collapsed"

Wolloch: /* Recommendations and advice */

2024-06-13T09:19:48Z

Recommendations and advice

← Older revision		Revision as of 09:19, 13 June 2024
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	:The following table highlights recommended PAW potentials for calculations involving many states above the Fermi energy in '''bold'''.		:The following table highlights recommended PAW potentials for calculations involving many states above the Fermi energy in '''bold'''.
	:~~These potentials are not necessarily superior (and even might be inferior) for calculations involving mostly occupied states, e.g., for [[Ionic_minimization\|structural relaxations]] or [[phonons]].~~ They are optimized for scattering properties high above the Fermi level and thus have advantages if many unoccupied states are involved, as for [[optical properties]] or [[many-body perturbation theory]].		:They are optimized for scattering properties high above the Fermi level and thus have advantages if many unoccupied states are involved, as for [[optical properties]] or [[many-body perturbation theory]]. Some results indicate that these GW potentials are also more accurate for ground-state-DFT calculations{{cite\|bosoni:natphysrev:2023}}, but the results should be very comparable with the standard potentials in most cases. Unless the uttermost accuracy is required, it is usually not worth paying the extra computational cost required<ref>For the potpaw_PBE.64 potential set, {{TAG\|ENMAX}} is on average ~26 eV (~11%) and {{TAG\|EAUG}} ~210 eV (42%) larger for the GW potentials compared to their standard counterparts with the same valency.</ref> for the GW potentials compared to their standard counterparts.

	:{\| class="wikitable sortable mw-collapsible mw-collapsed"		:{\| class="wikitable sortable mw-collapsible mw-collapsed"

Wolloch: /* Related tags and sections */

2024-06-12T14:09:39Z

Related tags and sections

← Older revision		Revision as of 14:09, 12 June 2024
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	{{FILE\|POTCAR}}, [[Prepare a POTCAR]], [[Available pseudopotentials]]		{{FILE\|POTCAR}}, [[Prepare a POTCAR]], [[Available pseudopotentials]]

	Theoretical background: [[Pseudopotentials]], [[~~Theory:~~ Pseudopotential basics]], [[Projector-augmented-wave formalism]]		Theoretical background: [[Pseudopotentials]], [[Pseudopotential basics]], [[Projector-augmented-wave formalism]]

	[[Category:Pseudopotentials]][[Category:Howto]]		[[Category:Pseudopotentials]][[Category:Howto]]

Wolloch: /* f-elements */

2024-06-12T14:02:15Z

f-elements

← Older revision		Revision as of 14:02, 12 June 2024
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	:Particularly problematic is the description of the transition from an itinerant (band-like) behavior observed at the beginning of each period to localized states towards the end of the period. For the 4<i>f</i> elements, this transition occurs already in La and Ce, whereas the transition sets in for Pu and Am for the 5<i>f</i> elements. A routine way to cope with the inabilities of present DFT functionals to describe the localized 4<i>f</i> electrons is to place the 4<i>f</i> electrons in the core. Such potentials are available and described below; however, they are expected to fail to describe magnetic properties arising <i>f</i> orbitals. Furthermore, PAW potentials in which the <i>f</i> states are treated as valence states are available, but these potentials are expected to fail to describe electronic properties when <i>f</i> electrons are localized. In this case, one might treat electronic correlation effects more carefully, e.g., by employing hybrid functionals or introducing on-site Coulomb interaction.		:Particularly problematic is the description of the transition from an itinerant (band-like) behavior observed at the beginning of each period to localized states towards the end of the period. For the 4<i>f</i> elements, this transition occurs already in La and Ce, whereas the transition sets in for Pu and Am for the 5<i>f</i> elements. A routine way to cope with the inabilities of present DFT functionals to describe the localized 4<i>f</i> electrons is to place the 4<i>f</i> electrons in the core. Such potentials are available and described below; however, they are expected to fail to describe magnetic properties arising <i>f</i> orbitals. Furthermore, PAW potentials in which the <i>f</i> states are treated as valence states are available, but these potentials are expected to fail to describe electronic properties when <i>f</i> electrons are localized. In this case, one might treat electronic correlation effects more carefully, e.g., by employing hybrid functionals or introducing on-site Coulomb interaction.

	:For some elements, soft versions (_s) are available as well. The semi-core <i>p</i> states are always treated as valence states, whereas the semi-core <i>s</i> states are treated as valence states only in the standard potentials. For most applications (oxides, sulfides), the standard version should be used since the soft versions might result in <i>s</i> ghost-states close to the Fermi-level (,e.g., Ce_s in ceria). The soft versions are, however, expected to be sufficiently accurate for calculations on intermetallic compounds.		:For some elements, [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|soft versions (_s)]] are available as well. The semi-core <i>p</i> states are always treated as valence states, whereas the semi-core <i>s</i> states are treated as valence states only in the standard potentials. For most applications (oxides, sulfides), the standard version should be used since the soft versions might result in <i>s</i> ghost-states close to the Fermi-level (,e.g., Ce_s in ceria). The soft versions are, however, expected to be sufficiently accurate for calculations on intermetallic compounds.

	====Lanthanides with fixed valence====		====Lanthanides with fixed valence====

Wolloch: /* d-elements */

2024-06-12T14:01:23Z

d-elements

← Older revision		Revision as of 14:01, 12 June 2024
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	:For the <i>d</i> elements, applies the same as for the alkali and earth-alkali metals: the semi-core <i>p</i> states and possibly the semi-core <i>s</i> states should be treated as valence states. In most cases, however, reliable results can be obtained even if the semi-core states are kept frozen.		:For the <i>d</i> elements, applies the same as for the alkali and earth-alkali metals: the semi-core <i>p</i> states and possibly the semi-core <i>s</i> states should be treated as valence states. In most cases, however, reliable results can be obtained even if the semi-core states are kept frozen.

	:When to switch from X_pv potentials to the X potentials depends on the required accuracy and the row for the 3<i>d</i> elements, even the Ti, V, and Cr potentials give reasonable results but should be used with uttermost care. 4<i>d</i> elements are the most problematic, and we advise using the X_pv potentials up to Tc_pv. For 5<i>d</i> elements the 5<i>p</i> states are rather strongly localized (below 3 Ry), since the 4<i>f</i> shell becomes filled. One can use the standard potentials starting from Hf, but we recommend performing test calculations. For some elements, X_sv potentials are available (,e.g., Nb_sv, Mo_sv, Hf_sv). These potentials usually have very similar energy cutoffs as the _pv potentials and can also be used. For HF-type and hybrid-functional calculations, we strongly recommend using the _sv and _pv potentials whenever possible.		:When to switch from X_pv potentials to the X potentials depends on the required accuracy and the row for the 3<i>d</i> elements, even the Ti, V, and Cr potentials give reasonable results but should be used with uttermost care. 4<i>d</i> elements are the most problematic, and we advise using the X_pv potentials up to Tc_pv. For 5<i>d</i> elements the 5<i>p</i> states are rather strongly localized (below 3 Ry), since the 4<i>f</i> shell becomes filled. One can use the standard potentials starting from Hf, but we recommend performing test calculations. For some elements, X_sv potentials are available (,e.g., Nb_sv, Mo_sv, Hf_sv). These potentials usually have very similar energy cutoffs as the _pv potentials and can also be used. For HF-type and hybrid-functional calculations, we strongly recommend using the [[Available_pseudopotentials#Different_variants_specified_by_the_suffix\|_sv and _pv]] potentials whenever possible.
	{{NB\|tip\|As a rule of thumb the <i>p</i> states should be treated as valence states for d-elements, if their eigenenergy <math>\epsilon</math> lies above 3 Ry.\|:}}		{{NB\|tip\|As a rule of thumb the <i>p</i> states should be treated as valence states for d-elements, if their eigenenergy <math>\epsilon</math> lies above 3 Ry.\|:}}