Category:Theory - Revision history

Huebsch at 12:27, 12 June 2024

2024-06-12T12:27:31Z

← Older revision		Revision as of 12:27, 12 June 2024
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	The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling~~, e~~.~~g., electronic~~-structure ~~calculations~~ and [[:~~Category:Molecular dynamics~~\|~~quantum-mechanical~~ molecular dynamics]]~~, from first principles~~.		The '''Vienna ab-initio simulation package''' (VASP) is a computer program for atomic scale materials modeling from first principles. A so-called ab-initio simulation generally entails
			* choosing the elements and a structure of the material,
			* [[Electronic minimization\|treating the electrons fully quantum mechanically]] and
			* optionally updating the ionic positions
			:* to [[ionic minimization\|minimize the forces]] and obtain a stable structure, or
			:* by means of Newton's equation of motion to perform [[MD\|molecular dynamics simulations]].

	VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[~~:Category:Hybrid functionals\|~~Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented ~~as well~~. Furthermore, Green’s functions methods based on [[~~:Category:Many-body perturbation theory\|~~many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more.		VASP computes an approximate solution to the many-body Schrödinger equation to obtain the [[electronic ground-state properties\|electronic ground state]]. This can either be done within density-functional theory (DFT) by solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation by solving the Roothaan equations. [[Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are also implemented. Furthermore, Green’s functions methods based on [[many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more to grant access to [[optical properties]].

	In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis ~~sets~~. ~~The interactions between~~ the electrons ~~and ions are described using~~ [[~~Available PAW potentials~~\|~~norm-conserving or ultrasoft pseudopotentials~~]], ~~or the~~ [[:Category:~~Projector-augmented-wave method~~\|~~projector-augmented~~-~~wave method~~]].		In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis using the [[projector-augmented-wave formalism\|projector-augmented-wave (PAW) method]]. This entails using PAW [[pseudopotentials]] to efficiently treat the relevant valence electrons while appropriately capturing the nodal features near the nuclei. To [[:Category:Electronic minimization\|determine the orbitals]] for the electronic ground state, VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]]. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density-mixing]] schemes to speed up the self-consistency cycle.

	To [[~~:Category:Electronic minimization\|determine~~ the electronic ~~ground~~ state]], ~~VASP makes use~~ of ~~efficient iterative matrix~~ [[~~ALGO\|diagonalization techniques~~]]~~, like~~ the ~~residual~~-~~minimization method with direct inversion of~~ the ~~iterative subspace (RMM-DIIS) or blocked Davidson algorithms~~. These ~~are coupled with highly efficient Broyden and Pulay~~ [[~~:Category:Density mixing\|density mixing~~]] ~~schemes to speed up~~ the ~~self-consistency cycle~~.		The ionic degrees of freedom can be updated by various algorithms ({{TAG\|IBRION}}) based on [[forces]] that are either obtained directly from the electronic state or from ab-intio quality force fields that were trained by machine learning. VASP is particularly strong in describing crystal structures due to the periodic boundary conditions it exploits. Naturally, these systems feature quantized vibrations in the form of [[phonons]] whose influence on the electronic ground state is taken into account by including [[electron-phonon coupling]].

			In this category, we collect theory pages from all the different areas VASP offers functionalities. These can also be reached from the corresponding category. For instance, the article on the [[Blocked-Davidson algorithm]] is also linked from the [[electronic minimization]] page.

Vaspmaster at 17:09, 9 November 2023

2023-11-09T17:09:34Z

← Older revision		Revision as of 17:09, 9 November 2023
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	To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.		To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.
	~~[[#KnownIssue1\| test]]~~

Vaspmaster at 17:09, 9 November 2023

2023-11-09T17:09:01Z

← Older revision		Revision as of 17:09, 9 November 2023
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	To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.		To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.
			[[#KnownIssue1\| test]]

Huebsch at 13:32, 8 April 2022

2022-04-08T13:32:26Z

← Older revision		Revision as of 13:32, 8 April 2022
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	The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling, e.g., electronic-structure calculations and [[:Category:Molecular dynamics\|quantum-mechanical molecular dynamics]], from first principles.		The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling, e.g., electronic-structure calculations and [[:Category:Molecular dynamics\|quantum-mechanical molecular dynamics]], from first principles.

	VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[:Category:Hybrid functionals\|Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented as well. Furthermore, Green’s functions methods based on [[:Category:Many-body perturbation theory\|many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW ~~method~~\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more.		VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[:Category:Hybrid functionals\|Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented as well. Furthermore, Green’s functions methods based on [[:Category:Many-body perturbation theory\|many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more.

	In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis sets. The interactions between the electrons and ions are described using [[Available PAW potentials\|norm-conserving or ultrasoft pseudopotentials]], or the [[:Category:Projector-augmented-wave method\|projector-augmented-wave method]].		In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis sets. The interactions between the electrons and ions are described using [[Available PAW potentials\|norm-conserving or ultrasoft pseudopotentials]], or the [[:Category:Projector-augmented-wave method\|projector-augmented-wave method]].

	To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.		To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.

Huebsch at 12:40, 7 April 2022

2022-04-07T12:40:03Z

← Older revision		Revision as of 12:40, 7 April 2022
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	VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[:Category:Hybrid functionals\|Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented as well. Furthermore, Green’s functions methods based on [[:Category:Many-body perturbation theory\|many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW method\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more.		VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[:Category:Hybrid functionals\|Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented as well. Furthermore, Green’s functions methods based on [[:Category:Many-body perturbation theory\|many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW method\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more.

	In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis sets. The interactions between the electrons and ions are described using [[Available PAW potentials\|norm-conserving or ultrasoft pseudopotentials]], or the [[:Category:~~PAW~~ method\|projector-augmented-wave method]].		In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis sets. The interactions between the electrons and ions are described using [[Available PAW potentials\|norm-conserving or ultrasoft pseudopotentials]], or the [[:Category:Projector-augmented-wave method\|projector-augmented-wave method]].

	To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.		To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.

Huebsch at 12:39, 7 April 2022

2022-04-07T12:39:22Z

← Older revision		Revision as of 12:39, 7 April 2022
Line 1:		Line 1:
	The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling, e.g., electronic-structure calculations and [[:Category:Molecular dynamics\|quantum-mechanical molecular dynamics]], from first principles.		The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling, e.g., electronic-structure calculations and [[:Category:Molecular dynamics\|quantum-mechanical molecular dynamics]], from first principles.

	VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[:Category:Hybrid functionals\|Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented as well. Furthermore, Green’s functions methods based on [[:Category:Many-body perturbation theory\|many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW method\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter ~~equation~~\|Bethe-Salpeter ~~equation~~]], and more.		VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[:Category:Hybrid functionals\|Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented as well. Furthermore, Green’s functions methods based on [[:Category:Many-body perturbation theory\|many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW method\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more.

	In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis sets. The interactions between the electrons and ions are described using [[Available PAW potentials\|norm-conserving or ultrasoft pseudopotentials]], or the [[:Category:PAW method\|projector-augmented-wave method]].		In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis sets. The interactions between the electrons and ions are described using [[Available PAW potentials\|norm-conserving or ultrasoft pseudopotentials]], or the [[:Category:PAW method\|projector-augmented-wave method]].

	To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.		To [[:Category:Electronic minimization\|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density mixing]] schemes to speed up the self-consistency cycle.

Huebsch: Huebsch moved page Theory to Category:Theory

2022-04-06T07:20:12Z

Huebsch moved page Theory to Category:Theory

← Older revision	Revision as of 07:20, 6 April 2022
(No difference)

Huebsch: Created page with "The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling, e.g., electronic-structure calculations and :Category:Molecular dyn..."

2022-04-06T07:19:34Z

Created page with "The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling, e.g., electronic-structure calculations and :Category:Molecular dyn..."

New page

The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling, e.g., electronic-structure calculations and [[:Category:Molecular dynamics|quantum-mechanical molecular dynamics]], from first principles.

VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[:Category:Hybrid functionals|Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented as well. Furthermore, Green’s functions methods based on [[:Category:Many-body perturbation theory|many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW method|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equation|Bethe-Salpeter equation]], and more.

In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis sets. The interactions between the electrons and ions are described using [[Available PAW potentials|norm-conserving or ultrasoft pseudopotentials]], or the [[:Category:PAW method|projector-augmented-wave method]].

To [[:Category:Electronic minimization|determine the electronic ground state]], VASP makes use of efficient iterative matrix [[ALGO|diagonalization techniques]], like the residual-minimization method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing|density mixing]] schemes to speed up the self-consistency cycle.

← Older revision		Revision as of 12:27, 12 June 2024
Line 1:		Line 1:
	The Vienna ab-initio simulation package (VASP) is a computer program for atomic scale materials modeling~~, e~~.~~g., electronic~~-structure ~~calculations~~ and [[:~~Category:Molecular dynamics~~\|~~quantum-mechanical~~ molecular dynamics]]~~, from first principles~~.		The '''Vienna ab-initio simulation package''' (VASP) is a computer program for atomic scale materials modeling from first principles. A so-called ab-initio simulation generally entails
			* choosing the elements and a structure of the material,
			* [[Electronic minimization\|treating the electrons fully quantum mechanically]] and
			* optionally updating the ionic positions
			:* to [[ionic minimization\|minimize the forces]] and obtain a stable structure, or
			:* by means of Newton's equation of motion to perform [[MD\|molecular dynamics simulations]].

	VASP computes an approximate solution to the many-body Schrödinger equation, either within density-functional theory (DFT), solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. [[~~:Category:Hybrid functionals\|~~Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are implemented ~~as well~~. Furthermore, Green’s functions methods based on [[~~:Category:Many-body perturbation theory\|~~many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more.		VASP computes an approximate solution to the many-body Schrödinger equation to obtain the [[electronic ground-state properties\|electronic ground state]]. This can either be done within density-functional theory (DFT) by solving the Kohn-Sham (KS) equations, or within the Hartree-Fock (HF) approximation by solving the Roothaan equations. [[Hybrid functionals]] that mix the Hartree-Fock approach with density-functional theory are also implemented. Furthermore, Green’s functions methods based on [[many-body perturbation theory]] are available in VASP. For instance, the [[:Category:GW\|GW method]], random-phase approximation, 2nd-order Møller-Plesset, [[:Category:Bethe-Salpeter equations\|Bethe-Salpeter equations]], and more to grant access to [[optical properties]].

	In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis ~~sets~~. ~~The interactions between~~ the electrons ~~and ions are described using~~ [[~~Available PAW potentials~~\|~~norm-conserving or ultrasoft pseudopotentials~~]], ~~or the~~ [[:Category:~~Projector-augmented-wave method~~\|~~projector-augmented~~-~~wave method~~]].		In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane-wave basis using the [[projector-augmented-wave formalism\|projector-augmented-wave (PAW) method]]. This entails using PAW [[pseudopotentials]] to efficiently treat the relevant valence electrons while appropriately capturing the nodal features near the nuclei. To [[:Category:Electronic minimization\|determine the orbitals]] for the electronic ground state, VASP makes use of efficient iterative matrix [[ALGO\|diagonalization techniques]]. These are coupled with highly efficient Broyden and Pulay [[:Category:Density mixing\|density-mixing]] schemes to speed up the self-consistency cycle.

	To [[~~:Category:Electronic minimization\|determine~~ the electronic ~~ground~~ state]], ~~VASP makes use~~ of ~~efficient iterative matrix~~ [[~~ALGO\|diagonalization techniques~~]]~~, like~~ the ~~residual~~-~~minimization method with direct inversion of~~ the ~~iterative subspace (RMM-DIIS) or blocked Davidson algorithms~~. These ~~are coupled with highly efficient Broyden and Pulay~~ [[~~:Category:Density mixing\|density mixing~~]] ~~schemes to speed up~~ the ~~self-consistency cycle~~.		The ionic degrees of freedom can be updated by various algorithms ({{TAG\|IBRION}}) based on [[forces]] that are either obtained directly from the electronic state or from ab-intio quality force fields that were trained by machine learning. VASP is particularly strong in describing crystal structures due to the periodic boundary conditions it exploits. Naturally, these systems feature quantized vibrations in the form of [[phonons]] whose influence on the electronic ground state is taken into account by including [[electron-phonon coupling]].

			In this category, we collect theory pages from all the different areas VASP offers functionalities. These can also be reached from the corresponding category. For instance, the article on the [[Blocked-Davidson algorithm]] is also linked from the [[electronic minimization]] page.