MOLPRO

31 EXPLICITLY CORRELATED METHODS 237
NOZ=1
NOX=1
FIX=1
FIX=2
FIXCAN=1
FIXCAN=-1
CABS=1
ORTHO CABS=1
THRABS=thrabs
THRCABS=thrcabs
Neglect Z terms (only 3B and 3C).
Neglect X terms (only 3A and 3B).
Use diagonal ansatz with fixed coefficient approximation (orbital invariant).
Use diagonal ansatz with fixed coefficient approximation. Evaluate
only first order energy expression, not the Hylleraas functional. Very
fast but less accurate and reliable!
Use diagonal ansatz with fixed coefficient approximation and canonical
orbitals. A non-iterative method is used to evaluate the energy.
This is equivalent to FIX=1,CANONICAL=1 and is most efficient.
As FIXCAN=1, but equations are solved iteratively (test purpose only).
Use CABS (default). If CABS=0 is given, CABS is disabled. However,
if RI BASIS=OPTRI, the orbital and OPTRI basis sets are automatically
merged, and then exactly the same results as with CABS=1
are obtained.
Construct CABS basis from orthogonal MOs and ABS basis rather
than AO and RI basis.
Threshold for smallest eigenvalue of S in auxiliary ABS (only used
with ORTHO CABS=1; default=THRCABS).
Threshold for smallest eigenvalue of S in CABS (default 1.d-8).
THRCABS REL=thrcabs rel Relative CABS threshold (default 1.d-9). The actual threshold
is max(thrcabs,eigmax*thrcabs rel, where eigmax is the
largest eigenvalue of the overlap matrix.
PRINT=level
DEBUG=level
SOLVE=0
SOLVE=1
SOLVE=2
SOLVE=3
CANONICAL=1
DOMSEL=1
Print parameter. PRINT=1 give information about all computed integrals
and the iterations.
Can be used to obtain extended debug print.
Use a most efficient pair-specific fully iterative method (default).
Use simple fully iterative method.
Use pair specific iterative method (more expensive).
Use pair specific non iterative method (most expensive, only with
canonical orbitals).
Use canonical orbitals and full domains.
Use full domains and localized orbitals (unless CANONICAL=1 is
given).
SCALE TRIP=1 Scale triples energy as explained in section 31.10.
SINGLES
CORE SINGLES
EXTGEN
For instance
If set to one, include CABS singles correction (default=1)
If set to one, include CABS singles correction for core orbitals (default=0)
For open-shell systems: If 1 (default,recommended), include all occupied
valence orbital pairs for mn in Tmn, i j independent of spin (as
described in J. Chem. Phys. 130, 054104 (2009), section II.E). If 0,
use only pairs mn where the spins of i and m, and j and n are equal.
ANSATZ=3C,fix=1,hybrid=1,canonical=1