$MOROKM group           (relevant if RUNTYP=EDA)                                
    This performs an analysis of the energy contributions                       
to dimerization (or formation of larger clusters of up to                       
ten monomers), according to the Morokuma-Kitaura and/or                         
Reduced Variational Space schemes.  The analysis is limited                     
to closed shell RHF monomers.  In other words, the monomers                     
should be distinct molecular species: avoid breaking                            
chemical bonds!  For more general energy decompositions,                        
see the $LMOEDA input group.  See also PIEDA in the FMO                         
    Solvation models are not supported.                                         
MOROKM = a flag to request Morokuma-Kitaura decomposition.                      
         (default is .TRUE.)                                                    
RVS    = a flag to request "reduced variation space"                            
         decomposition.  This differs from the Morokuma                         
         analysis.  One or the other or both may be                             
         requested in the same run.  (default is .FALSE.)                       
Generally speaking, RVS handles non-orthogonality of                            
monomers better.  When diffuse functions are used, the                          
MOROKM analysis sometimes fails, but RVS will work.                             
BSSE   = a flag to request basis set superposition error                        
         be computed.  You must ensure that CTPSPL is                           
         selected.  This option applies only to MOROKM                          
         decompositions, as a basis superposition error is                      
         automatically generated by the RVS scheme.  This                       
         is not the full Boys counterpoise correction, as                       
         explained in the reference.  (default is .FALSE.)                      
                           * * *                                                
The inputs here control how the RHF supermolecule, whose                        
coordinates are given in the $DATA input group, is divided                      
into two or more monomers.                                                      
IATM   = An array giving the number of atoms in each of                         
         the monomer.  Up to ten monomers may be defined.                       
         Your input in $DATA must have all the atoms in                         
         the first monomer defined before the atoms in the                      
         second monomer, before the third monomer...  The                       
         number of atoms belonging to the final monomer                         
         can be omitted.  There is no sensible default for                      
         IATM, so don't omit it from your input.                                
ICHM   = An array giving the charges of the each monomer.                       
         The charge of the final monomer may be omitted,                        
         as it is fixed by ICH in $CONTRL, which is the                         
         total charge of the supermolecule.  The default                        
         is neutral monomers, ICHM(1)=0,0,0,...                                 
EQUM   = an array to indicate all monomers are equivalent                       
         by symmetry (in addition to containing identical                       
         atoms). If so, which is not often true, then only                      
         the unique computations will be done.                                  
         (default is .FALSE.,.FALSE., ...)                                      
                        * * *                                                   
CTPSPL = a flag to decompose the interaction energy into                        
         charge transfer plus polarization terms.  This                         
         is most appropriate for weakly interacting                             
         monomers. (default is .TRUE.)                                          
CTPLX  = a flag to combine the CT and POL terms into a                          
         single term.  If you select this, you might want                       
         to turn CTPSPL off to avoid the extra work that                        
         that decomposition entails, or you can analyze                         
         both ways in the same run.  (default is .FALSE.)                       
RDENG  = a flag to enable restarting, by reading the                            
         lines containing "FINAL ENERGY" from a previous                        
         run.  The $EMORO group is single lines read under                      
         format A16,F20.10 containing the energies, and a                       
         card $END to complete.  The 16 chars = anything.                       
         (default is .FALSE.)                                                   
   The present implementation has some quirks:                                  
1. The initial guess of the monomer orbitals is not                             
controlled by $GUESS.  The program first looks for a $VEC1,                     
$VEC2, ... group for each monomer.  The orbitals must be                        
obtained for the identical coordinates which that monomer                       
has within the supermolecule.  If any $VECn groups are                          
found, they will be MOREAD.  If any are missing, the guess                      
for that monomer will be constructed by HCORE.  Check your                      
monomer energies carefully!  The initial guess orbitals for                     
the supermolecule are formed from a block diagonal matrix                       
containing the monomer orbitals.                                                
2. The use of symmetry is turned off internally.                                
3. Spherical harmonics (ISPHER=1) may not be used.                              
4. There is no direct SCF option.  File ORDINT will be a                        
full C1 list of integrals.  File AOINTS will contain                            
whatever subset of these is needed for each particular                          
decomposition step.  So extra disk space is needed compared                     
to RUNTYP=ENERGY.                                                               
5. This run type applies only to ab initio RHF treatment of                     
the monomers.  To be quite specific: this means that DFT                        
(which involves a grid, not just integrals) will not work,                      
nor will MOPAC's approximated 2e- integrals                                     
6. This kind of calculation will run in parallel.                               
Quirks 1, 3 and 4 can be eliminated by using PIEDA if only                      
two monomers are present. For more monomers PIEDA results                       
will slightly differ. PIEDA is a special case of FMO, q.v.                      
C.Coulson  in "Hydrogen Bonding", D.Hadzi, H.W.Thompson,                        
   Eds., Pergamon Press, NY, 1957, pp 339-360.                                  
C.Coulson  Research, 10, 149-159 (1957).                                        
K.Morokuma  J.Chem.Phys. 55, 1236-44 (1971).                                    
K.Kitaura, K.Morokuma  Int.J.Quantum Chem. 10, 325 (1976).                      
K.Morokuma, K.Kitaura  in "Chemical Applications of                             
   Electrostatic Potentials", P.Politzer,D.G.Truhlar, Eds.                      
   Plenum Press, NY, 1981, pp 215-242.                                          
The method coded is the newer version described in the 1976                     
and 1981 papers.  In particular, note that the CT term is                       
computed separately for each monomer, as described in the                       
words below eqn. 16 of the 1981 paper, not simultaneously.                      
Reduced Variational Space:                                                      
W.J.Stevens, W.H.Fink, Chem.Phys.Lett. 139, 15-22(1987).                        
A comparison of the RVS and Morokuma decompositions can be                      
found in the review article: "Wavefunctions and Chemical                        
Bonding" M.S.Gordon, J.H.Jensen in "Encyclopedia of                             
Computational Chemistry", volume 5, P.V.R.Schleyer, editor,                     
John Wiley and Sons, Chichester, 1998.                                          
BSSE during Morokuma decomposition:                                             
R.Cammi, R.Bonaccorsi, J.Tomasi                                                 
Theoret.Chim.Acta 68, 271-283(1985).                                            
The present implementation:                                                     
"Energy decomposition analysis for many-body interactions,                      
 and application to water complexes"                                            
W.Chen, M.S.Gordon   J.Phys.Chem. 100, 14316-14328(1996)                        

generated on 7/7/2017