Combined functionals

GGAKey

it is an universal keyword allowing to manually construct arbitrary linear combinations of other functionals. Even fractional Hartree-Fock exchange can be specified. This keyword is to be followed by a string of functionals with associated weights. The syntax is NAME=WEIGHT .... Example:

.DFT
 GGAKey hf=0.2 slater=0.8 becke=0.72 lyp=0.81 vwn3=0.19

BLYP

is a sum of Slater functional, Becke88 correction and LYP correlation functional. It is equivalent to GGAKey slater=1 becke=1 lyp=1

B3LYP

hybrid functional [144] equivalent to: GGAKey hf=0.2 slater=0.8 becke=0.72 lyp=0.81 vwn=0.19.

B3LYP-G

hybrid functional with VWN3 form used for correlation--this is the form used by the Gaussian quantum chemistry program. This functional can be explicitely set up by GGAKey hf=0.2 slater=0.8 becke=0.72 lyp=0.81 vwn3=0.19

BP86

Becke88 exchange functional and Perdew86 correlation functional. The explicit form is: GGAKey slater=1 becke=1 pz81=1 p86c=1

B3P86

variant of B3LYP with VWN3 used for local correlation and P86 for the nonlocal part. GGAKey hf=0.2 slater=0.8 becke=0.72 p86c=0.81 vwn3=1

CAMB3LYP

Coulomb Attenuated Method Functional of Yanai, Tew and Handy[145]. This functional accepts additional arguments alpha, beta and mu to modify the fraction of HF exchange for short-range interactions, additional fraction of HF exchange for long-range interaction and the interaction switching factor $\mu$. This input can be specified as follows:

.DFT
 CAMB3LYP alpha=0.190 beta=0.460 mu=0.330

KT1

Slater-VWN5 functional with the KT GGA correction [132,146]. GGAKey slater=1 vwn=1 kt=-0.006

KT2

differs from KT1 only in that the weights of the Slater and VWN5 functionals are from an empirical fit [132,146]. GGAKey slater=1.07173 vwn=0.576727 kt=-0.006

KT3

a hybrid functional of Slater, OPTX and KT exhange with the LYP correlation functional [147]. The explicit form is GGAKey slater=1.092 kt=-0.004 lyp=0.864409 optx=-0.925452

OLYP

is the sum of the OPTX exchange functional with the LYP correlation functional [136]. GGAKey slater=1.05151 optx=-1.43169 lyp=1
Mixed functionals such as OP86 and OPW91 may be constructed with GGAKey.

PBE0

a hybrid functional of Perdew, Burke and Ernzerhof with 0.2 weight of exact exchange, 0.75 of PBEx functional and PBEC correlation functional [148]. GGAKey hf=0.25 pbex=0.75 pbec=1

PBE

same as above but with exchange estimated exclusively by PBEx functional [149]. This is the form used by eg. CADPAC and NWChem quantum chemistry programs. GGAKey pbex=1 pbec=1
Observe that quantum chemistry program Molpro uses PW91c correlation functional instead of PBEC which is equivalent to following: GGAKey pbex=1 PW91c=1.

BPW91

is a sum of Slater functional, Becke correction and PW91 correlation functional. GGAKey slater=1 becke=1 pw91c=1