[exchange_functional]
type: character*(32)
doc: name of the exchange functional
interface: ezfio, provider, ocaml
default: sr_pbe

[correlation_functional]
type: character*(32)
doc: name of the correlation functional
interface: ezfio, provider, ocaml
default: sr_pbe

[HF_exchange]
type: double precision
doc: Percentage of HF exchange in the DFT model
interface: ezfio,provider,ocaml
default: 0.