MOLPRO

29 LOCAL CORRELATION TREATMENTS 209
29.4 Summary of directives
The same standard directives as in the canonical programs, e.g., OCC, CLOSED, CORE, WF,
ORBITAL are also valid in the local methods. In addition, there are some directives which only
apply to local calculations:
LOCAL
MULTP
DOMAIN
MERGEDOM
REGION
ENEPART
SAVE
START
Invokes local methods and allows to specify the same options as on
the command line.
As LOCAL, but multipole approximations are used for distant pairs.
Define domains manually (not recommended).
Allows to merge domains
Allows to select regions of a molecule to be treated at a certain level
of theory.
Analysis of pair energies.
Save domains and LCCSD amplitudes.
Restart with domains and LCCSD amplitudes from a previous calculation.
29.5 General Options
LOCAL=local
LOCORB=option
LOC METHOD=method
Determines which method is used:
LOCAL=0: Conventional (non-local) calculation.
LOCAL=1: Local method is simulated using canonical MOs. The local
basis is used only at an intermediate stage to update the amplitudes
in each iteration (only for testing).
LOCAL=2: Calculation is done in local basis, but without using local
blocking (i.e. full matrices are used). This is the most expensive
method and only for testing.
LOCAL=3: Fully local calculation (obsolete).
LOCAL=4: Fully local calculation (default). This is the fastest method
for large molecules with many weak pairs and requires minimum
memory.
If this option is given and option> 0, the orbitals are localized using
the Pipek-Mezey technique. If this option is not given or option=0
(default), the orbitals are localized unless localized orbitals are found
in the orbital record (cf. ORBITAL directive and LOCALI command).
In the latter case, the most recent localized orbitals are used. Setting
option=-1 switches the localization off. If option> 1 the localized
orbitals are printed. Note: Boys localization can only be performed
using the LOCALI command. The program will use the Boys orbitals
if they are found in the orbital record and the LOCORB option is absent
or option≤ 0.
This option allows to select between Pipek-Mezey (method=PM) or
Natural Orbitals (method=NBO) localization. If Pipek-Mezey orbitals
are requested, the default Boughton-Pulay domain selection will be
used. When method=NBO, the domain selection will be based on the
NPA charges, with NPASEL=0.03 (by default). In both cases, the domain
selection parameter can be explicitly given (cf. DOMSEL and