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$SCFMI group (optional, relevant if SCFTYP=RHF)
The Self Consistent Field for Molecular Interactions
(SCF-MI) method is a modification of the usual Roothaan
equations that avoids basis set superposition error (BSSE)
in intermolecular interaction calculations, by expanding
each monomer's orbitals using only its own basis set.
Thus, the resulting orbitals are not orthogonal. The
presence of a $SCFMI group in the input triggers the use
of this option.
The implementation is limited to ten monomers, treated
at the RHF level. The energy, gradient, and therefore
semi-numerical hessian are available. The SCF step may be
run in direct SCF mode, and parallel calculation is also
enabled. The calculation must use Cartesian Gaussian AOs
only, not spherical harmonics. The SCF-MI driver differs
from normal RHF calculations, so not all converger methods
are available. Finally, this option is not compatible with
electron correlation treatments (DFT, MP2, CI, or CC).
The first 3 parameters must be given. All atoms of a
fragment must appear consecutively in $DATA.
NFRAGS = number of distinct fragments present. Both
the supermolecule and its constituent monomers
must be well described as closed shells by RHF
wavefunctions.
NF = an array containing the number of doubly
occupied
MOs for each fragment.
MF = an array containing the number of atomic basis
functions located on each fragment.
ITER = maximum number of SCF-MI cycles, overriding
the usual MAXIT value. (default is 50).
DTOL = SCF-MI density convergence criteria.
(default is 1.0d-10)
ALPHA = possible level shift parameter.
(default is 0.0, meaning shifting is not used)
DIISON = a flag to active the DIIS convergence.
(default is .TRUE.)
MXDIIS = the maximum number of previous effective Fock
and
overlap matrices to be used in DIIS
(default=10)
DIISTL = the density change value at which DIIS starts.
(default=0.01)
A Huckel guess is localized by the Boys procedure onto each
fragment to provide starting orbitals for each:
ITLOC = maximum number of iteration in the localization
step (Default is 50)
CNVLOC = convergence parameter for the localization.
(default is .01).
IOPT = prints additional debug information.
= 0 standard outout (default)
= 1 print for each SCF-MI cycle MOs, overlap
between the MOs, CPU times.
= 2 print some extra informations in secular
systems solution.
==========================================================
"Modification of Roothan Equations to exclude BSSE
from Molecular Interaction calculations"
E. Gianinetti, M. Raimondi, E. Tornaghi
Int. J. Quantum Chem. 60, 157-166 (1996)
"Implementation of Gradient optimization algorithms
and Force Constant computations in BSSE-free direct
and conventional SCF approaches"
A. Famulari, E. Gianinetti, M. Raimondi, M. Sironi
Int. J. Quantum Chem. 69, 151-158 (1997)
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generated on 7/7/2017