Subject: DFT functionals, reference implementation

From: [email-masked]
Date: Mon, 8 Nov 1999 09:31:35 +0100 (MET)

Hi all,

Matt Challacombe suggested to have a "public domain" collection of
subroutines which implemente the evaluation of density functionals.

Before collecting the "functional" subroutines, our community should set
up examples with reference energies. For example, it was not so easy to
figure out EXACTLY what has been implemented in GAUSSIAN under the name
"LDA" or "VWN", a part which also enters functionals like B3LYP.
I suggest a collection of atomic reference data, since many programs can
converge DFT energies for atoms (using a specified Gaussian basis set) to
nano-Hartree accuracy. For the beginning, four examples are sufficient:

He atom, ground state                     ("unpolarized")
He atom, 1s2s triplet state               ("fully polarized")
N  atom, quartet state, spin-restricted   ("partially polarized")
N  atom, quartet state, spin-Unrestricted

I have collected data for some DFT programs around and total energies
vary quite a bit for functionals like LDA, BP86 (<-- different "local" 
parts) etc.

What about establishing a "consensus" set of total energies first?

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Christoph van Wullen       | Fon (University):  +49 234 32 26485
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