Category:Constrained-random-phase approximation: Difference between revisions

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All tags and articles that deal with CRPA calculations are members of this category.
The '''constrained random-phase approximation''' (cRPA) is a method that allows the calculation of the effective interaction parameter <math>U</math>, <math>J</math>, and <math>J'</math> for model Hamiltonians.
The main idea is to neglect the screening effects of specific target states in the screened Coulomb interaction <math>W</math> of the [[The GW approximation of Hedin's equations|GW method]].
The resulting partially screened Coulomb interaction is evaluated in a [[Wannier functions|localized basis]] that spans the target space and is described by the model Hamiltonian.
The target space is usually low-dimensional and therefore allows for the application of a higher-level theory, such as dynamical-mean-field theory (DMFT).


== Theoretical Background ==
More information about cRPA is found on the following page:
The constrained random-phase approximation (CRPA) is a method that allows to calculate the effective interaction parameter U, J and J' for model Hamiltonians.
The main idea is to neglect screening effects of specific '''target states''' in the screened Coulomb interaction W of the [[The GW approximation of Hedin's equations|GW method]].
The resulting partially screened Coulomb interaction is usually evaluated in a localized basis that spans the target space and is described by the model Hamiltonian.
The target space is usually low-dimensional and therefore allows for the application of a higher level theory, such as dynamical mean field theory.
 
More information about CRPA is found on the following page:


[[Constrained–random-phase–approximation_formalism]]
[[Constrained–random-phase–approximation_formalism]]


== How to ==
[[Category:VASP|ACFDT]][[Category:Many-body perturbation theory]]
 
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[[Category:VASP|ACFDT]][[Category:Many-body perturbation theory]][[Category:VASP6]]

Latest revision as of 13:58, 25 March 2025

The constrained random-phase approximation (cRPA) is a method that allows the calculation of the effective interaction parameter , , and for model Hamiltonians. The main idea is to neglect the screening effects of specific target states in the screened Coulomb interaction of the GW method. The resulting partially screened Coulomb interaction is evaluated in a localized basis that spans the target space and is described by the model Hamiltonian. The target space is usually low-dimensional and therefore allows for the application of a higher-level theory, such as dynamical-mean-field theory (DMFT).

More information about cRPA is found on the following page:

Constrained–random-phase–approximation_formalism

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