Exchange correlation functionalsΒΆ

The available LDA exchange-correlation functionals are:

  • LDA functionals
    1. VWN
    2. Ceperly-Adler
    3. Perdew-Zunger 81
    4. RPA
    5. Wigner Interpolation Functional
    6. Kohn-Sham exchange only (Xalpha with alpha =2/3)
    7. Gunnarsson-Lundquist

The first GGA functional (PW91) was implemented in 1991. THe following GGA functionals are currently available.

  • GGA functionals
    1. Becke 1988 exchange functional (B88)
    2. Perdew-Wang 91 functional (PW91)
    3. Perdew-Burke-Ernzerhof 96 functional (PBE)
    4. Revised Perdew-Burke-Ernzerhof 96 functional (PBE)
    5. RPBE

The PBE functional is the default functional. In the above lines, the words in the bracket are the keywords that you can use to select the exchange and correlation functional of your choice. THis is specified in the file called( CLUSTER) file. For example, to specify use the “BPW91” functional you will use GGA-B88*GGA-PW91 in the first line in the CLUSTER file.

Work on implementation of Minnesota functionals is in progress.