   GCASdeloc   GCASdeloc   GCASdeloc   GCASdeloc   GCASdeloc   

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Note: If you know GCAS, GCASdeloc is a simplified version, without
reference to use of local orbitals


Definition: merge the orbitals or several rasscf orbital files, to
get average orbitals



Method:
          Get Occupied, Active and Virtuals from several RasOrb files. Some of
          them appear more than once, as they were generated by different
          rasscf calculations. In that case they are almost identical.

Step 1   Actives: 
          Buils overlap matrix between actives, diagonalise. One gets almost
          integer eigenvalues. If ~1: the active was generated once. The 
          eigenvector corresponds to the active orbital. If eigenvalue ~n (n>0)
          the state was present in n rasscf calculations. The eingenvector will
          result in an average vector of the n states. If eigenvalue ~0, the
          eigenvector should be eliminated, as it is the result or a linear
          dependency. there are n-1 eliminated vectors for a eigen value equal 
          to n.

Step 2    Once constructed the Active space, one must build the occupied and
          virtual spaces
          Occupied : 
          It would be convenient to use the same method, but the number of
          cumulated occupied orbitals could be to large. it would be impossible
          to diagonalise
          Then: 
          - take RasOrb file number 1
          - loop on orbitals
          - for occupied n, look for an equivalent in all other files
            if one equivalent is found, and if it corresponds to an active, 
            forget the orbital
          - Otherwise, one has nf orbitals, where nf is the number of RasOrb files
          - Apply same method, as it was done for actives (overlap matrix,
            diagonalisation, get only eigenvalue equal to nf.
          Virtuelles : as for occupied

Step 4    hierarchised orthogonalisation act, then occ+virt

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Input files: (on $WorkDir) : 
 - Info et Mono files
 - RasOrb files
Input files: (on $CurrDir)
 - rasin files (data files for rasscf calculations.


Input data:
1.
 &gcas prefix='...',nprint=..,symm= ,ninac=  ,noac=   ,nelac= /
   prefix : compulsory
   symm : needed on old molcas versions, if one wants a molden file.
   ninac,noac: number of doubly occupied, and active orbitals in each
   symmetry.
   nelac: number of active electrons.
   ninac,numac and nelac correspond to the final active space, once merged
   all active orbitals.
2.
 &ras namelists, one for each RasOrb file
 &ras input=   ,'rasorb=   /
 input: name of rasscf input file     (is on CurrDir!)
 rasorb: name of rasOrb file          (is on WorkDir!)



Output: sortie :- A RasOrb file with many actives ($Project.GCasOrb)
            

Example of data:

gcasdeloc << EOF
 &gcas prefix='Ni.',nprint=0,ninac=35,24,35,24,31,21,31,21,
 noac=1,0,1,0,1,0,1,0,nelac=6 /
 &ras input='rasin_357S',rasorb='Ni.RasOrb_357S' /
 &ras input='rasin_1357T',rasorb='Ni.RasOrb_1357T' /
EOF


