The error introduced from a CCSD(T) calculation with a finite basis set can be corrected from second-order corrections of the the interference-corrected MP2-F12 (INT-MP2-F12) (Ref. [132]). The approximate CCSD(T)-INT-F12 at the basis set limit is given from

E_{CCSD(T)/CBS} E_{CCSD(T)} + F^{ij}[e_{ij}^{MP2-F12} - e_{ij}^{MP2}] . |
(10.26) |

From

`$ricc2`

select the `ccsd(t)`

method
and add the keyword $ricc2 ccsd(t) intcorrThen, switch on the

`f12`

method (approximation `A`

or `B`

, `inv`

or `fixed`

).
The corrected CCSD(T)-INT-F12 energy will be printed in the end of the calculation.
It is highly recommended to start the CCSD(T)-INT-F12 calculation
from a converged SCF calculation with symmetry, which is transfromed to `$rir12`

submenu.
A table with the corrected second-order pair-electron energies and the corresponding
interference factors can also be printed in the output
by using the keyword `intcorr all`

instead of `intcorr`

.