These keywords indicate that additional basis functions are to be added to the basis set or density fitting basis set specified in the route section for the calculation (respectively). These basis functions appear in a separate section in the input stream, using any of the valid formats (which are described in detail in the discussion of theGenkeyword).
ExtraBasisis most useful for supplying basis functions for elements undefined in a standard basis set. Itcannotbe used to replace a definition within a built-in basis set, and attempting to do so will result in an error. All basis functions specified with this keyword areaddedto the ones in the basis set specified in the route section. For these reasons,Genis often easier to use thanExtraBasis; consult the description for that keyword before deciding to use this one.
ExtraDensityBasisis ignored if no density fitting basis is specified in the route.
Gen,Pseudo,GenECP,GFInput,GFPrint
The following job uses the 6-31G(d,p) basis set along with anadditionaldiffuse function on all of the carbon atoms:
# HF/6-31G(d,p) ExtraBasis …title sectionmolecule specificationC 0 SP 1 1.00 0.4380000000D-01 0.1000000000D+01 0.1000000000D+01 ****
The following job supplies additional functions for both the basis set and for density fitting:
#p rblyp/6-31g*/dga1 extrabasis extradensitybasis 6d HCl using the internally stored 6-31g* AO basis & DGA1 fitting set, adding f functions to the AO basis, and f & g fitting functions 0,1 cl h,1,1.29 ! here are some extra AO polarization functions cl 0Additional basis set functionsF 1 1.00 0.000000000000 0.7500000000D+00 0.1000000000D+01 **** h 0 p 1 1.00 0.000000000000 0.1612777588D+00 0.1000000000D+01 **** ! here are some extra fitting functions. cl 0Additional density fitting functionsf 1 1.5 g 1 1.5 **** h 0 spd 1 0.32 ****
The following job reads in extra basis set data from an external file:
# B3LYP/6-31++G(d) ExtraBasis B3LYP/6-31++G(d) with extra diffuse functionsmolecule specification@tripleplus.gbs
Last update: 23 April 2013