# Differences

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explicitly_correlated_methods [2022/01/24 17:09] qianli Update citation |
explicitly_correlated_methods [2022/03/01 08:33] (current) werner [Basis sets] |
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In MOLPRO the F12 integrals can only be computed using density fitting (DF) approximations. The many electron integrals are approximated by resolutions of the identity (RI) expansions. Thus, F12 calculations require three different basis sets: the orbital (AO) basis, the DF basis, and the RI basis. | In MOLPRO the F12 integrals can only be computed using density fitting (DF) approximations. The many electron integrals are approximated by resolutions of the identity (RI) expansions. Thus, F12 calculations require three different basis sets: the orbital (AO) basis, the DF basis, and the RI basis. | ||

- | We recommend as AO basis sets the augmented correlation consistent basis sets (denoted AVnZ) or the specially optimized correlation consistent F12 basis sets (denoted VnZ-F12, cf. K.A. Peterson and H.-J. Werner, [[https:// | + | We recommend as AO basis sets the augmented correlation consistent basis sets (denoted AVnZ) or the specially optimized correlation consistent F12 basis sets (denoted VnZ-F12, cf. K.A. Peterson and H.-J. Werner, [[https://, [A]VnZ-F12, or VnZ-PP-F12 orbital basis sets are used, suitable density fitting (DF) basis and resolution of the identity (RI) basis sets are automatically chosen. For the AVnZ orbital basis sets, AVnZ/MP2FIT amd VnZ/JKFIT basis sets are used by default for the DF and RI, respectively. The associated optimized CABS basis set of Peterson et al. can be chosen by specifying ''[a]VnZ-F12 and [a][c]VnZ-PP-F12 orbital basis, the associated CABS (OPTRI) basis sets are used by default. However, OPTRI sets are not yet available for all elements, and in such cases an alternative RI basis must be explicitly specified using the '' |

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+ | Other basis sets can be chosen using the '' | ||

This is an example for using multiple basis sets for density fitting and resolution of the identity | This is an example for using multiple basis sets for density fitting and resolution of the identity |