$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) ==========================================================

generated on 7/7/2017