Local-density approximation: Difference between revisions

Revision as of 00:45, 26 April 2017

Revision as of 00:50, 26 April 2017

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* Chachiyo's correlation functional: <math>\epsilon_{c} = a \ln \left( 1 + \frac{b}{r_s} + \frac{b}{r_s^2} \right) .</math> <ref>{{cite journal | title = Communication: Simple and accurate uniform electron gas correlation energy for the full range of densities | author = Teepanis Chachiyo | journal = J. Chem. Phys. | volume = 145 | pages = 021101 | year = 2016 | doi = 10.1063/1.4958669 | issue = 2}}</ref>

The parameters “a” and “b” do not come from fitting to the Monte Carlo data, but from a constraint that the functional approaches the high-density theoretical limit. The Chachiyo's formula yields more accurate results than the standard LDA formulas. <ref>{{cite journal | title = A simpler ingredient for a complex calculation | author = Richard J. Fitzgerald | journal = Physics Today | volume = 69 | pages = 20 | year = 2016 | doi = 10.1063/PT.3.3288 | issue = 9}}</ref>. Keeping the same functional form, the parameter "b" has also been fitted to the Monte Carlo data, providing a better agreement. <ref>{{cite journal | title = Comment on “Communication: Simple and accurate uniform electron gas correlation energy for the full range of densities” [J. Chem. Phys. 145, 021101 (2016)] | author = Valentin V. Karasiev | journal = J. Chem. Phys. | volume = 145 | pages = 157101 | year = 2016 | doi = 10.1063/1.4964758 | issue = 2}}</ref>.