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Kinetic-energy functionals

In order to use different GGA approximations of the non-additive kinetic potential, the flag -k string must be used. Here string is the acronym used to identify a given GGA kinetic energy approximation, that can be selected among the following functionals:

For example, the command

                      FDE -p 3 -k lc94
approximates the non-additive kinetic contribution to the embedding potential through the functional derivative of LC94 kinetic energy functional.

A pure electrostatic embedding can be also performed with FDE script, where the embedding potential required by a subsystem A to account for the presence of the B one will be merely:

vemb(r) = vBext(r) + vJ[ρB](r) (15.9)

with vBext(r) and vJ[ρB](r) the electrostatic potentials generated respectively by the nuclei and electron density of the subsystem B. To perform an electrostatic embedding calculation use
                      FDE  -p 3 -k electro
and can be performed for both Kohn-Sham (only for LDA/GGA exchange-correlation functionals) and Hartree-Fock methods.

The electrostatic embedding is implemented only for testing purpose. It resembles an electrostatic embedding with external point-charges and/or point-dipoles, but it is ``exact'' as it is based on the whole densities (i.e. it considers all multipole moments of the density and the polarizabilies at all orders).

Equivalent command: --kin string

fde.input option: kin= string


next up previous contents index
Next: FDE charged subsystems Up: Options Previous: Subsystem definition   Contents   Index
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