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** Next:** 24.3 Brueckner coupled-cluster calculations,
** Up:** 24 THE CLOSED SHELL
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##

24.2 Quadratic configuration interaction, QCI

`QCI` or `QCISD` performs quadratic configuration interaction, QCISD. Using the
`QCI(T)` or `QCISD(T)` commands, the contributions of connected triples
are also computed by perturbation theory. Normally, no further input
is needed if the `QCI` card follows the corresponding HF-SCF.
Otherwise, occupancies and orbitals can be specified as in the CI
program. For modifying DIIS directives, see section 24.7.

For avoiding error exits in case of no convergence, see `CCSD(T)`.

molpro@molpro.net 2018-04-21