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

      Specifies which eigenvector of the totally symmetric part of the block-factored Hessian is to be followed uphill in a transition state search. Eigenvectors are indexed by their eigenvalues -- the lowest eigenvalue is 1, the next lowest is 2, etc. The default is 1, which should always be used if you are not looking for a specific transition state which you know corresponds to motion along a different mode. In the future, relatively sophisticated generation of a guessed eigenvector will be implemented, but this is the way things are for now. Of course, this keyword has no meaning if :term:`CFOUR_METHOD <CFOUR_METHOD (CFOUR)>` is not set to TS.

      * **Type**: integer
      * **Default**: 1

