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

      Specifies which algorithm is used for :term:`CFOUR_ANHARMONIC <CFOUR_ANHARMONIC (CFOUR)>` =VIBROT, VPT2, and FULLQUARTIC calculations. If STANDARD (=0) is chosen, then simply invoking ``xcfour`` will cause a complete job to be run with all second-derivative calculations being done in series. If PARALLEL (=1), then the job stops after the second-derivative calculation at the reference geometry and generates out all input geometries for the remaining calculation. These can be then processed in "parallel" (currently not recommended). Note that it is recommended to carry out all calculations with PARALLEL, even when the actual calculation is carried out in a sequential mode.

      * **Type**: string
      * **Possible Values**: STANDARD, PARALLEL
      * **Default**: STANDARD

