# Counterpoise Correct

Code author: Robert M. Parrish

`cp`(name[, func, check_bsse, molecule])

  The cp function computes counterpoise-corrected two-body interaction energies for complexes composed of arbitrary numbers of monomers.

  Aliases: | counterpoise_correct(), counterpoise_correction()
  Returns: | (float) Counterpoise-corrected interaction energy in Hartrees.
  PSI variables: |

  - `CP-CORRECTED 2-BODY INTERACTION ENERGY`
  - `UNCP-CORRECTED 2-BODY INTERACTION ENERGY`

  Caution

  Some features are not yet implemented. Buy a developer a coffee.

  - No values of func besides energy have been tested.
  - Table print-out needs improving. Add some PSI variables.

  Parameters:

  - name (string) –

    `'scf'` || `'ccsd(t)'` || etc.

    First argument, usually unlabeled. Indicates the computational method to be applied to the molecule. May be any valid argument to `energy()`; however, SAPT is not appropriate.

  - func (function) –

    `energy` || `optimize` || `cbs`

    Indicates the type of calculation to be performed on the molecule and each of its monomers. The default performs a single-point `energy('name')`, while `optimize` perfoms a geometry optimization on each system, and `cbs` performs a compound single-point energy. If a nested series of python functions is intended (see Function Intercalls), use keyword `cp_func` instead of `func`.

  - check_bsse (boolean) –

    `'on'` || `'off'`

    Indicates whether to additionally compute un-counterpoise corrected monomers and thus obtain an estimate for the basis set superposition error.

  - molecule (molecule) –

    `h2o` || etc.

    The target molecule, if not the last molecule defined.

  Examples: |

      >>> # [1] counterpoise-corrected density-fitted mp2 interaction energy
      >>> cp('df-mp2')

`n_body`(name[, func, bsse, max_n_body, do_total, external, external_monomers, molecule])