:term:`OCC_TOLERANCE <OCC_TOLERANCE (FNOCC)>`
"""""""""""""""""""""""""""""""""""""""""""""

      Cutoff for occupation of MP2 virtual NOs in FNO-QCISD/CCSD(T). Virtual NOs with occupations less than :term:`OCC_TOLERANCE <OCC_TOLERANCE (FNOCC)>` will be discarded. This option is only used if :term:`NAT_ORBS <NAT_ORBS (FNOCC)>` = true.

      * **Type**: :ref:`conv double <op_c_conv>`
      * **Default**: 1.0e-6

