ADF 2006

Avaliable Functionals

LDA

Xonly: The pure-exchange electron gas formula. Technically this is identical to the Xalpha form 
(see next)with a value 2/3 for the X-alpha parameter.
Xalpha: the scaled (parameterized) exchange-only formula. When this option is used you may 
(optionally) specify the X-alpha parameter by typing a numerical value after the string Xalpha 
(separated by a blank). If omitted this parameter takes the default value 0.7
VWN: the parameterization of electron gas data given by Vosko, Wilk and Nusair.

GGA

Exchange Part
Becke: the gradient correction proposed in 1988 by Becke.
PW86x: the correction advocated in 1986 by Perdew-Wang.
PW91x: the exchange correction proposed in 1991 by Perdew-Wang.
mPWx: the modified PW91 exchange correction proposed in 1998 by Adamo-Barone.
PBEx: the exchange correction proposed in 1996 by Perdew-Burke-Ernzerhof.
RPBEx: the revised PBE exchange correction proposed in 1999 by Hammer-Hansen-Norskov.
revPBEx: the revised PBE exchange correction proposed in 1998 by Zhang-Wang.
mPBEx: the modified PBE exchange correction proposed in 2002 by Adamo-Barone.
OPTX: the OPTX exchange correction proposed in 2001 by Handy-Cohen.

Correlation Part
Perdew: the correlation term presented in 1986 by Perdew [30].
PBEc: the correlation term presented in 1996 by Perdew-Burke-Ernzerhof [26] .
PW91c: the correlation correction of Perdew-Wang (1991), see [24].
LYP: the Lee-Yang-Parr 1988 correlation correction [31-33].

 Exchange and Correlation Parts In One Stroke
BP86: this is equivalent to Becke + Perdew together.
PW91: this is equivalent to pw91x + pw91c together.
mPW: this is equivalent to mPWx + pw91c together.
PBE: this is equivalent to PBEx + PBEc together.
RPBE: this is equivalent to RPBEx + PBEc together.
revPBE: this is equivalent to revPBEx + PBEc together.
mPBE: this is equivalent to mPBEx + PBEc together.
BLYP: this is equivalent to Becke (exchange) + LYP (correlation).
OLYP: this is equivalent to OPTX (exchange) + LYP (correlation).
OPBE: this is equivalent to OPTX (exchange) + PBEc (correlation).
XLYP: this is equivalent to XLYPx (exchange, not available separately from LYP) + LYP (correlation).
LB94: this refers to the XC functional of Van Leeuwen and Baerends.
KT1: this refers to the KT1 functional of Keal and Tozer.
KT2: this refers to the KT2 functional of Keal and Tozer.