:term:`CFOUR_FROZEN_CORE <CFOUR_FROZEN_CORE (CFOUR)>`
"""""""""""""""""""""""""""""""""""""""""""""""""""""

      Specifies whether in the correlation treatment all electron (OFF =0) or only the valence electrons (ON =1) are considered. This keyword provides an alternative to the :term:`CFOUR_DROPMO <CFOUR_DROPMO (CFOUR)>` keyword, as it allows frozen-core calculation without explicitly specifying the corresponding inner-shell orbitals.

      * **Type**: :ref:`boolean <op_c_boolean>`
      * **Default**: false

