Questions tagged [exchange-correlation]

Questions concerning exchange-correlation terms in materials modeling calculations.

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12
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1answer
98 views

What's the physics contained in the exchange-correlation functional in the framework of KS-DFT?

This question is inspired by this post. In the Kohn-Sham framework of density functional theory, the total energy is expressed as: $$E=E_{kin}^{non}+E_{ext}+E_{H}+E_{xc}$$ in which The first term is ...
9
votes
1answer
225 views

How does libxc calculate the potential of GGA functionals?

If the GGA xc energy is defined as $$ E_{xc}[n] = \int n(\mathbf{r}) \varepsilon_{xc}[n(\mathbf{r}), \nabla n(\mathbf{r})]\ d\mathbf{r}, $$ the potential can be written as $$ V_{xc}[n] = \varepsilon_{...
3
votes
1answer
85 views

The projector augmented wave (PAW) method, pseudopotentials (PP), and exchange correlation functionals

Disclaimer: Assume the questioner is a novice in DFT Is PAW an improvement over the pseudopotential method? In terms of Perdew, Burke, and Ernzerhof (PBE) parameterization, what is the difference ...
8
votes
1answer
63 views

Parameterization in the generalised gradient approximation (GGA)

Disclaimer: Assume the person asking is a novice in DFT and condensed matter physics in general. In the localized density approximation (LDA), the exchange correlation potential is considered a ...
28
votes
2answers
635 views

Is there any DFT code or software that has the option to use this exact exchange-correlation energy functional?

Most of the conventional DFT codes or software use LDA, GGA, meta-GGA, PBE, etc. exchange-correlation functionals, but I'm wondering if there is any DFT code or software that uses the new generation ...