MOLPRO

18 ORBITAL LOCALIZATION 126
GROUP,3.1,5.1,-8.1 this group includes orbitals 3,5,6,7,8 in symmetry 1
Orbitals in different groups are localized independently. Orbitals not included in any group are
unchanged.
18.6.4 Localization between groups (OFFDIAG)
OFFDIAG
If this card is present, localize between groups instead of within groups.
18.7 Ordering of localized orbitals
ORDER,type
If type=CHARGE, the orbitals are ordered according to their charge centroids (default).
If type=FOCK, the orbitals are ordered according to increasing diagonal elements of the fock
operator (PIPEK) or increasing Coulson-additive orbital energies (BOYS). This requires a Fock
operator from the preceding energy calculation. For localization of Hartree-Fock orbitals, this
operator is stored in the dump record and automatically found. For localization of MCSCF
orbitals, an effective fock operator is computed from the MCSCF density matrix (see DENSITY
option). Alternatively, a dump record of a previous SCF calculation can be specified on the
FOCK card, and then the fock operator is read from this record. For degenerate orbitals, further
ordering according to the the coordinates of charge centres is attempted (first according to largest
z-coordinates, then according to x, then y).
This card does not apply to NLMO localization.
18.7.1 No reordering (NOORDER)
NOORDER
If this card is present, the localized orbitals are not reordered. This is useful if localized orbitals
are used as starting guess, and it is intended that their order remains unchanged.
18.7.2 Ordering using domains (SORT)
SORT,[THRCHCHG=charge][THREIG=eps],GROUP=igrp],[REVERT],centrelist
This directive only works for Pipek-Mezey localization. The orbitals are ordered according to
domains and the given centrelist. The contributions of the centres to domains are determined by
Löwdin charges. Only centres with charges greater than THRCHCHG (default 0.4) are included
in these domains. The orbitals are reordered according to the following criteria:
1.) The primary centre in a domain is the one with largest charge, the secondary centre the
one with the next largest charge. Orbitals are reordered separately within each localization
group. First all orbitals are sorted so that the primary centres are in the order of the given
centrelist. Orbitals with primary centres which are not in centrelist come last.