$ELG group              (polymer elongation calculation)
 
    This group of parameters provides control of elongation
calculations, which steadily increase the size of aperiodic
polymers, by adding attacking monomers to the end of an
existing chain.  The existing chain consists of two parts:
an A region, with a frozen electron density, farthest from
the new monomer, and a B region at whose end the monomer
attacks.  The wavefunction of the B region and the new
monomer are optimized quantum mechanically.  Disk files
containing integrals and/or wavefunction information must
be saved from one elongation run to the next.
 
    A large number of examples are provided with the source
code distribution, see ~/gamess/tools/elg for this, perhaps
starting with the (gly)5, (gly)6, (gly)7 examples.  See the
literature cited below for more help.
 
NELONG = a flag to activate an elongation calculation,
          0 means normal GAMESS run (default)
          1 same as 0 but without reorientation of geometry
          2 means elongation starting cluster calculation,
            this initiates a chain's A and B regions.
          3 implies the monomer elongation of the chain.
 
NATM   = NUMBER OF ATOMS IN A-REGION
         Coordinates of the A-region atoms must be listed
         at the beginning of the input geometry in $DATA
 
NASPIN = multiplicity of the A-region
 
NTMLB  = NUMBER OF TERMINAL ATOMS IN B-REGION
 
NCT    = CONTROLLER FOR AO-CUT
         0 means no AO-cut
         1 means AO-cut activated
 
IPRI   = PRINT LEVEL
         0 minimum printing (default)
         3 debugging printing
 
LDOS   = LOCAL DENSITY OF STATES CALCULATION
         0 means no LDOS calculation
         1 means LDOS calculation
 
I2EA   = READ-IN 2E-INTEGRALS FOR A-REGION
         0 means A-region 2e-integrals are recalculated
         1 means A-region 2e-integrals are read from a
           previous calculation
 
ATOB   = Flag to shift one unpaired electron to the A- or
         the B-region, for covalently bonded A and B.
         .TRUE. means shift one electron to B-region
         .FALSE. means shift one electron to A-region
 
For more information on this method, see
 
A.Imamura, Y.Aoki, K.Maekawa
      J.Chem.Phys. 95, 5419-5431(1991)
Y.Aoki, A.Imamura  J.Chem.Phys. 97, 8432-8440(1992)
Y.Aoki, S.Suhai, A.Imamura
      Int.J.Quantum Chem. 52, 267-280(1994)
Y.Aoki, S.Suhai, A.Imamura
      J.Chem.Phys. 101, 10808-10823(1994)
 
and particularly the new implementation described in
 
"Application of the elongation method to nonlinear optical
properties: finite field approach for calculating static
electric (hyper)polarizabilities"
  F.L.Gu, Y.Aoki, A.Imamura, D.M.Bishop, B.Kirtman
  Mol.Phys. 101, 1487-1494(2003)
"A new localization scheme for the elongation method"
  F.L.Gu, Y.Aoiki, J.Korchowiec, A.Imamura, B.Kirtman
  J.Chem.Phys. 121, 10385-10391(2004)
"Elongation method with cutoff technique for linear SCF
scaling"
  J.Korchowiec, F.L.Gu, A.Imamura, B.Kirtman, Y.Aoki
  Int.J.Quantum Chem. 102, 785-794(2005)
"Elongation method at Restricted Open-Shell Hartree-Fock
level of theory"
  J.Korchowiec, F.L.Gu, Y.Aoki
  Int.J.Quantum Chem.  105, 875-882(2005)
 
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