Nudged elastic bands - Revision history

Csheldon: /* Step 2 */

2026-03-30T08:03:35Z

Step 2

← Older revision		Revision as of 08:03, 30 March 2026
Line 11:		Line 11:

	==== Step 2 ====		==== Step 2 ====
	Create a parent directory with enumerated subdirectories. For <math>n</math> ~~images~~, create <math>(n + 2)</math> subdirectories and label them with their index starting from <code>0</code>. The foldername must always have 2 characters, pad with 0 if necessary. E.g. in case of 3 images		Create a parent directory with enumerated subdirectories. For <math>n</math> {{TAG\|IMAGES}}, create <math>(n + 2)</math> subdirectories and label them with their index starting from <code>0</code>. The foldername must always have 2 characters, pad with 0 if necessary. E.g. in case of 3 images

	mycalc -- 00		mycalc -- 00

Wolloch: /* Possible issues and advice on how to address it */

2025-11-27T09:44:18Z

Possible issues and advice on how to address it

← Older revision		Revision as of 09:44, 27 November 2025
Line 52:		Line 52:
	While this does not affect the VASP calculations, it can complicate result visualization.		While this does not affect the VASP calculations, it can complicate result visualization.
	{{NB\|warning\|The NEB feature presented here cannot be applied to structural transitions. Changing the lattice would require a different algorithm referred to as variable-cell NEB that is not available within VASP.}}		{{NB\|warning\|The NEB feature presented here cannot be applied to structural transitions. Changing the lattice would require a different algorithm referred to as variable-cell NEB that is not available within VASP.}}
	{{NB\|tip\|For more advanced calculations, consider using the [https://theory.cm.utexas.edu/vtsttools/index.html Transition State Tools for VASP].}}		{{NB\|tip\|For more advanced calculations, consider using the [https://theory.cm.utexas.edu/vtsttools/index.html Transition State Tools for VASP (VTST)].}}

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

Wolloch: /* Possible issues and advice on how to address it */

2025-11-27T09:43:08Z

Possible issues and advice on how to address it

← Older revision		Revision as of 09:43, 27 November 2025
Line 52:		Line 52:
	While this does not affect the VASP calculations, it can complicate result visualization.		While this does not affect the VASP calculations, it can complicate result visualization.
	{{NB\|warning\|The NEB feature presented here cannot be applied to structural transitions. Changing the lattice would require a different algorithm referred to as variable-cell NEB that is not available within VASP.}}		{{NB\|warning\|The NEB feature presented here cannot be applied to structural transitions. Changing the lattice would require a different algorithm referred to as variable-cell NEB that is not available within VASP.}}
	{{NB\|tip\|For more advanced calculations, consider using the [https://~~vtstools~~.~~readthedocs~~.~~io/en~~/~~latest~~/index.html Transition State Tools for VASP].}}		{{NB\|tip\|For more advanced calculations, consider using the [https://theory.cm.utexas.edu/vtsttools/index.html Transition State Tools for VASP].}}

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

Huebsch: /* How to set up an NEB calculation */

2025-10-15T12:16:08Z

How to set up an NEB calculation

← Older revision		Revision as of 12:16, 15 October 2025
Line 11:		Line 11:

	==== Step 2 ====		==== Step 2 ====
	Create a ~~calculation~~ directory with <math>n+2</math> ~~enumerated~~ subdirectories ~~where~~ <~~math~~>n</~~math~~> ~~is number of images~~. The ~~name of the directory~~ must have ~~two~~ characters with ~~leading~~ 0. E.g. in case of 3 images		Create a parent directory with enumerated subdirectories. For <math>n</math> images, create <math>(n + 2)</math> subdirectories and label them with their index starting from <code>0</code>. The foldername must always have 2 characters, pad with 0 if necessary. E.g. in case of 3 images

	mycalc -- 00		mycalc -- 00
Line 29:		Line 29:

	==== Step 4 ====		==== Step 4 ====
	Create an {{FILE\|INCAR}} file in the ~~root calculation~~ directory (e.g. <code>mycalc</code>) and set the tag {{TAG\|IMAGES}} to the number of intermediate structures.		Create an {{FILE\|INCAR}} file in the parent directory (e.g. <code>mycalc</code>) and set the tag {{TAG\|IMAGES}} to the number of intermediate structures.
	This will introduce tangential springs to maintain equidistance among images during the relaxation process.		This will introduce tangential springs to maintain equidistance among images during the relaxation process.
	Control the strength with the {{TAG\|SPRING}} tag, where negative values (like the default of -5) activate the NEB method.		Control the strength with the {{TAG\|SPRING}} tag, where negative values (like the default of -5) activate the NEB method.
Line 38:		Line 38:
	==== Step 5 ====		==== Step 5 ====
	Create the remaining input files {{FILE\|KPOINTS}} and {{FILE\|POTCAR}}.		Create the remaining input files {{FILE\|KPOINTS}} and {{FILE\|POTCAR}}.
	For the NEB method, we recommend that all input files, except the {{TAG\|POSCAR}}, {{TAG\|WAVECAR}} and {{TAG\|CHGCAR}} file, reside in the ~~root calculation~~ directory.		For the NEB method, we recommend that all input files, except the {{TAG\|POSCAR}}, {{TAG\|WAVECAR}} and {{TAG\|CHGCAR}} file, reside in the parent directory.
	Then, run VASP by executing it in the ~~root calculation~~ directory (e.g. <code>mycalc</code>) to optimize the reaction path.		Then, run VASP by executing it in the parent directory (e.g. <code>mycalc</code>) to optimize the reaction path.

	== Possible issues and advice on how to address it ==		== Possible issues and advice on how to address it ==

Huebsch: /* Related tags and articles */

2025-10-15T11:21:18Z

Huebsch: /* Possible issues and advice on how to address it */

2025-10-15T11:18:46Z

Possible issues and advice on how to address it

← Older revision		Revision as of 11:18, 15 October 2025
Line 51:		Line 51:
	Failing to do so introduces artificial forces, causing the images to drift apart.		Failing to do so introduces artificial forces, causing the images to drift apart.
	While this does not affect the VASP calculations, it can complicate result visualization.		While this does not affect the VASP calculations, it can complicate result visualization.
			{{NB\|warning\|The NEB feature presented here cannot be applied to structural transitions. Changing the lattice would require a different algorithm referred to as variable-cell NEB that is not available within VASP.}}
	{{NB\|tip\|For more advanced calculations, consider using the [https://vtstools.readthedocs.io/en/latest/index.html Transition State Tools for VASP].}}		{{NB\|tip\|For more advanced calculations, consider using the [https://vtstools.readthedocs.io/en/latest/index.html Transition State Tools for VASP].}}

Huebsch at 09:19, 15 October 2025

2025-10-15T09:19:07Z

← Older revision		Revision as of 09:19, 15 October 2025
Line 7:		Line 7:

	==== Step 1 ====		==== Step 1 ====
	Carefully ~~converge~~ the fixed structures of your elastic band, i.e., the initial and the final state.		Carefully [[Structure optimization\|optimize the structure]] of the fixed structures of your elastic band, i.e., the initial and the final state.
	Remember that in the subsequent steps, the elastic band will be attached to these fixed structures, so any error will affect the transition path you obtain.		Remember that in the subsequent steps, the elastic band will be attached to these fixed structures, so any error will affect the transition path you obtain.

	==== Step 2 ====		==== Step 2 ====
			Create a calculation directory with <math>n+2</math> enumerated subdirectories where <math>n</math> is number of images. The name of the directory must have two characters with leading 0. E.g. in case of 3 images

			mycalc -- 00
			\|_ 01
			\|_ 02
			\|_ 03
			\|_ 04

			Place the {{FILE\|POSCAR}} file of the initial state in <code>00</code> and {{FILE\|POSCAR}} file of the final state in the last directory (<code>04</code> in the example).

			==== Step 3 ====
	Construct an initial guess for the intermediate structures.		Construct an initial guess for the intermediate structures.
	You may use a script like in the [~~[Collective jumps~~ of a ~~Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation\|tutorial]~~] or develop your own method.		You may use a script like in the [https://vasp.at/tutorials/latest/transition_states/part1/#transition_states-e01 tutorial on self-diffusion of a Si atom to a vacancy site] or develop your own method.
	~~This script in the tutorial also offers the option to remove center-of-mass motion.~~		The intermediate images should be somewhat close to the real transition path; otherwise, the optimization of the elastic band may fail.
	~~These~~ intermediate images should be somewhat close to the real transition path; otherwise, the optimization of the elastic band may fail.		Place the {{FILE\|POSCAR}} files corresponding to these intermediate structures in subdirectories <code>01</code>, <code>02</code>, etc.
	Place the {{FILE\|POSCAR}} files corresponding to these intermediate structures in subdirectories 01, 02, etc.
	{{NB\|mind\|Make sure that the {{FILE\|POSCAR}} contains the same ordering of elements for initial, final, and intermediate states. It is highly recommended to minimize the number of images used to an absolute minimum. Convergence to the ground state is faster with fewer images. Starting with a single image between the two endpoints and increasing the number of images after the initial run has converged is often a prudent approach.}}		{{NB\|mind\|Make sure that the {{FILE\|POSCAR}} contains the same ordering of elements for initial, final, and intermediate states. It is highly recommended to minimize the number of images used to an absolute minimum. Convergence to the ground state is faster with fewer images. Starting with a single image between the two endpoints and increasing the number of images after the initial run has converged is often a prudent approach.}}

	==== Step 3 ====		==== Step 4 ====
	Create an {{FILE\|INCAR}} file in the root directory and set the tag {{TAG\|IMAGES}} to the number of intermediate structures.		Create an {{FILE\|INCAR}} file in the root calculation directory (e.g. <code>mycalc</code>) and set the tag {{TAG\|IMAGES}} to the number of intermediate structures.
	This will introduce tangential springs to maintain equidistance among images during the relaxation process.		This will introduce tangential springs to maintain equidistance among images during the relaxation process.
	~~You can control~~ the strength with the {{TAG\|SPRING}} tag, where negative values (like the default of -5) activate the NEB method.		Control the strength with the {{TAG\|SPRING}} tag, where negative values (like the default of -5) activate the NEB method.
	It is important not to use excessively large values for {{TAG\|SPRING}}, as it can hinder convergence.		It is important not to use excessively large values for {{TAG\|SPRING}}, as it can hinder convergence.
	The default value generally provides reliable results.		The default value generally provides reliable results.
	You should also set {{TAG\|IBRION}}, {{TAG\|ISIF}}, {{TAG\|NSW}}, and other [[Category:Ionic minimization\|relaxation-related tags]].		You should also set {{TAG\|IBRION}}, {{TAG\|ISIF}}, {{TAG\|NSW}}, and other [[Category:Ionic minimization\|relaxation-related tags]].

	==== Step 4 ====		==== Step 5 ====
	Create the remaining input files {{FILE\|KPOINTS}} and {{FILE\|POTCAR}}.		Create the remaining input files {{FILE\|KPOINTS}} and {{FILE\|POTCAR}}.
	For the NEB method, we recommend that all input files, except the {{TAG\|POSCAR}}, {{TAG\|WAVECAR}} and {{TAG\|CHGCAR}} file, reside in the root directory.		For the NEB method, we recommend that all input files, except the {{TAG\|POSCAR}}, {{TAG\|WAVECAR}} and {{TAG\|CHGCAR}} file, reside in the root calculation directory.
	Then, run VASP ~~until~~ the path ~~is optimized~~.		Then, run VASP by executing it in the root calculation directory (e.g. <code>mycalc</code>) to optimize the reaction path.

	== Possible issues and advice on how to address it ==		== Possible issues and advice on how to address it ==
Line 45:		Line 55:
	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|IMAGES}}, {{TAG\|SPRING}}, {{TAG\|IBRION}}		{{TAG\|IMAGES}}, {{TAG\|SPRING}}, {{TAG\|IBRION}}

			[https://vasp.at/tutorials/latest/transition_states/part1/#transition_states-e01 Tutorial on self-diffusion of a Si atom to a vacancy site]

	[[Collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation]]		[[Collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation]]

Wolloch: /* Possible issues and advice on how to address it */

2025-04-11T10:05:01Z

Possible issues and advice on how to address it

← Older revision		Revision as of 10:05, 11 April 2025
Line 41:		Line 41:
	Failing to do so introduces artificial forces, causing the images to drift apart.		Failing to do so introduces artificial forces, causing the images to drift apart.
	While this does not affect the VASP calculations, it can complicate result visualization.		While this does not affect the VASP calculations, it can complicate result visualization.
	{{NB\|tip\|For more advanced calculations, consider using the [https://~~theory~~.cm.~~utexas.edu~~/~~vtsttools~~/ Transition State Tools for VASP].}}		{{NB\|tip\|For more advanced calculations, consider using the [https://vtstools.readthedocs.io/en/latest/index.html Transition State Tools for VASP].}}

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

Huebsch: Huebsch moved page Construction:Nudged elastic bands to Nudged elastic bands without leaving a redirect

2023-10-20T11:26:49Z

Huebsch moved page Construction:Nudged elastic bands to Nudged elastic bands without leaving a redirect

← Older revision		Revision as of 11:26, 20 October 2023
(No difference)

Huebsch at 11:25, 20 October 2023

2023-10-20T11:25:48Z

← Older revision		Revision as of 11:21, 15 October 2025
Line 58:		Line 58:

	[https://vasp.at/tutorials/latest/transition_states/part1/#transition_states-e01 Tutorial on self-diffusion of a Si atom to a vacancy site]		[https://vasp.at/tutorials/latest/transition_states/part1/#transition_states-e01 Tutorial on self-diffusion of a Si atom to a vacancy site]

			Lecture on modeling chemical reactions (and transition states) using [https://youtu.be/mLK7CtDmw0A static approaches]

	[[Collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation]]		[[Collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation]]

	[[TS search using the NEB Method]]		[[TS search using the NEB Method]]

	== References ==		== References ==
	<references/>		<references/>

	[[Category:Transition states]][[Category:Ionic minimization]][[Category:Howto]]		[[Category:Transition states]][[Category:Ionic minimization]][[Category:Howto]]

← Older revision		Revision as of 11:25, 20 October 2023
Line 8:		Line 8:
	==== Step 1 ====		==== Step 1 ====
	Carefully converge the fixed structures of your elastic band, i.e., the initial and the final state.		Carefully converge the fixed structures of your elastic band, i.e., the initial and the final state.
	Remember that in the subsequent steps, the elastic band will be attached to these fixed structures so any error will affect the transition path you obtain.		Remember that in the subsequent steps, the elastic band will be attached to these fixed structures, so any error will affect the transition path you obtain.

	==== Step 2 ====		==== Step 2 ====
Line 14:		Line 14:
	You may use a script like in the [[Collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation\|tutorial]] or develop your own method.		You may use a script like in the [[Collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation\|tutorial]] or develop your own method.
	This script in the tutorial also offers the option to remove center-of-mass motion.		This script in the tutorial also offers the option to remove center-of-mass motion.
	These intermediate images should be somewhat close to the real transition path otherwise the optimization of the elastic band may fail.		These intermediate images should be somewhat close to the real transition path; otherwise, the optimization of the elastic band may fail.
	Place the {{FILE\|POSCAR}} files corresponding to these intermediate structures in subdirectories 01, 02, ...		Place the {{FILE\|POSCAR}} files corresponding to these intermediate structures in subdirectories 01, 02, etc.
	{{NB\|mind\|Make sure that the {{FILE\|POSCAR}} contains the same ordering or elements for initial, final and intermediate states. It is highly recommended to minimize the number of images used to an absolute minimum. Convergence to the ground state is faster with fewer images. Starting with a single image between the two endpoints and increasing the number of images after the initial run has converged is often a prudent approach.}}		{{NB\|mind\|Make sure that the {{FILE\|POSCAR}} contains the same ordering of elements for initial, final, and intermediate states. It is highly recommended to minimize the number of images used to an absolute minimum. Convergence to the ground state is faster with fewer images. Starting with a single image between the two endpoints and increasing the number of images after the initial run has converged is often a prudent approach.}}

	==== Step 3 ====		==== Step 3 ====
Line 24:		Line 24:
	It is important not to use excessively large values for {{TAG\|SPRING}}, as it can hinder convergence.		It is important not to use excessively large values for {{TAG\|SPRING}}, as it can hinder convergence.
	The default value generally provides reliable results.		The default value generally provides reliable results.
	You should also set {{TAG\|IBRION}}, {{TAG\|ISIF}}, {{TAG\|NSW}}, and other relaxation-related tags.		You should also set {{TAG\|IBRION}}, {{TAG\|ISIF}}, {{TAG\|NSW}}, and other [[Category:Ionic minimization\|relaxation-related tags]].

	==== Step 4 ====		==== Step 4 ====
	Create the remaining input files {{FILE\|KPOINTS}} and {{FILE\|POTCAR}}.		Create the remaining input files {{FILE\|KPOINTS}} and {{FILE\|POTCAR}}.
	For the NEB method, we recommend that all input files, except the {{TAG\|POSCAR}}, {{TAG\|WAVECAR}} and {{TAG\|CHGCAR}} file, reside in the root directory.		For the NEB method, we recommend that all input files, except the {{TAG\|POSCAR}}, {{TAG\|WAVECAR}} and {{TAG\|CHGCAR}} file, reside in the root directory.
	Then run VASP until the path is optimized.		Then, run VASP until the path is optimized.


	== Possible issues and advice on how to address it ==		== Possible issues and advice on how to address it ==
	One challenge with the NEB method arises from its non-linear constraint, which restricts movements to a hyper-plane perpendicular to the current tangent.		One challenge with the NEB method arises from its non-linear constraint, which restricts movements to a hyper-plane perpendicular to the current tangent.
	This characteristic can lead to convergence issues with the ~~Conjugate Gradient~~ (CG) algorithm ({{TAG\|IBRION}}=2).		This characteristic can lead to convergence issues with the conjugate-gradient (CG) algorithm ({{TAG\|IBRION}}=2).
	In such cases, it is advisable to use alternative algorithms like the RMM-DIIS algorithm ({{TAG\|IBRION}}=1) or the quick-min algorithm ({{TAG\|IBRION}}=3).		In such cases, it is advisable to use alternative algorithms like the RMM-DIIS algorithm ({{TAG\|IBRION}}=1) or the quick-min algorithm ({{TAG\|IBRION}}=3).
	Additionally, the equidistant images tend to deviate from this constraint in the initial steps.		Additionally, the equidistant images tend to deviate from this constraint in the initial steps.
	To address this, applying a low dimensionality parameter ({{TAG\|IBRION}}=1, {{TAG\|NFREE}}=2) in the initial steps or using steepest descent minimization without line optimization ({{TAG\|IBRION}}=3, {{TAG\|SMASS}}=2) can help pre-converge the images.		To address this, applying a low dimensionality parameter ({{TAG\|IBRION}}=1, {{TAG\|NFREE}}=2) in the initial steps or using steepest descent minimization without line optimization ({{TAG\|IBRION}}=3, {{TAG\|SMASS}}=2) can help pre-converge the images.

	If all degrees of freedom are allowed to relax (e.g., in isolated molecules or surfaces), it is crucial to ensure that the sum of all positions remains consistent across all cells.		If all degrees of freedom are allowed to relax, (e.g., in isolated molecules or surfaces), it is crucial to ensure that the sum of all positions remains consistent across all cells.
	Failing to do so introduces artificial forces, causing the images to drift apart.		Failing to do so introduces artificial forces, causing the images to drift apart.
	While this does not affect the VASP calculations, it can complicate result visualization.		While this does not affect the VASP calculations, it can complicate result visualization.

	{{NB\|tip\|For more advanced calculations, consider using the [https://theory.cm.utexas.edu/vtsttools/ Transition State Tools for VASP].}}		{{NB\|tip\|For more advanced calculations, consider using the [https://theory.cm.utexas.edu/vtsttools/ Transition State Tools for VASP].}}

Line 51:		Line 49:

	[[TS search using the NEB Method]]		[[TS search using the NEB Method]]

	== References ==		== References ==
	<references/>		<references/>

	[[Category:Transition states]][[Category:Ionic minimization]][[Category:Howto]]		[[Category:Transition states]][[Category:Ionic minimization]][[Category:Howto]]