Editing ADF 2006 (section)

== 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.

'''HYBRID'''

 B3LYP: ADF uses VWN5 in B3LYP. functional (20% Hartree-Fock exchange) by 
 Stephens-Devlin-Chablowski-Frisch.
 
 B3LYP*: modified B3LYP functional (15% Hartree-Fock exchange) by Reiher-Salomon-Hess.
 
 B1LYP: functional (25% Hartree-Fock exchange) by Adamo-Barone.
 
 KMLYP: functional (55.7% Hartree-Fock exchange) by Kang-Musgrave.
 
 O3LYP: functional (12% Hartree-Fock exchange) by Cohen-Handy.
 
 X3LYP: functional (21.8% Hartree-Fock exchange) by Xu-Goddard.
 
 BHandH: 50% Hartree-Fock exchange, 50% LDA exchange, and 100% LYP correlation.
 
 BHandHLYP: 50% Hartree-Fock exchange, 50% LDA exchange, 50% Becke88 exchange, and 100% LYP 
 correlation.
 
 B1PW91: functional by (25% Hartree-Fock exchange) Adamo-Barone.
 
 mPW1PW: functional (42.8% Hartree-Fock exchange) by Adamo-Barone.
 
 mPW1K: functional (25% Hartree-Fock exchange) by Lynch-Fast-Harris-Truhlar.
 
 PBE0: functional (25% Hartree-Fock exchange) by Ernzerhof-Scuseria and by Adamo-Barone,
 hybrid form of PBE.
 
 OPBE0: functional (25% Hartree-Fock exchange) by Swart-Ehlers-Lammertsma, hybrid form of OPBE.