MOZYME example: Print Eigenvectors

The MOZYME method uses localized molecular orbitals.  When keyword VECTORS is used, MOZYME will print out the LMOs is a highly compressed form.  If eigenvectors are required, the occupied and virtual LMOs must be converted into eigenvectors.  The keywords for this are EIGEN and VECTORS or ALLVECS, if all the eigenvectors are needed. Be careful if all the eigenvectors are requested - the output can be large.

Data-set:

 MOZYME Eigen Vectors
Optimize the geometry of formic acid 

   O    0.0  0    0.0 0    0.0 0   0  0  0
   C    1.20 1    0.0 0    0.0 0   0  0  0
   O    1.32 1  116.8 1    0.0 0   2  1  0
   H    0.98 1  123.9 1    0.0 0   3  2  1
   H    1.11 1  127.3 1  180.0 0   2  1  3    

To see the difference between the MOZYME eigenvectors and conventional, run the data set with and without MOZYME and look at the eigenvectors in the output file.  In MOZYME, the occupied set of eigenvectors and eigenvalues are printed, then the virtual set.  This reflects the different methods of generating them.

Because the calculation of the eigenvectors involves matrix algebra, the computational effort rises as the cube of the size of the system, and can rapidly become very great.  For this reason, do not request eigen vectors unless absolutely necessary.