These options specify
which inner orbitals are frozen in post-SCF calculations. Gaussian 03 adds
some additional options to the ones already available in the program .
This indicates "frozen-core," and it implies that inner-shells are excluded from
the correlation calculation. This is the default calculation mode. Note that FC,
Full, RW and Window are mutually exclusive. It is which is
equivalent to FreezeG2 for the 6-31G and 6-311G basis sets and to FreezeNobleGasCore
for all other basis sets, except that the outer s and p core orbitals of 3rd row
and later alkalai and alkalai earth atoms are not frozen (in accord with the G2/G3
In post-SCF calculations
the largest noble gas core is frozen. FrzNGC is a synonym for this option.
In post-SCF calculations, the
next to largest noble gas core is frozen. That is, the outermost core orbitals
are retained. FrzINGC and FC1 are synonyms for this option.
Freeze orbitals according to the G2 convention: d orbitals
of main group elements are frozen, but the outer sp core of 3rd row and later
alkalai and alkalai earth elements are kept in the valence.
This specifies that all electrons be included in a correlation calculation.
The "read window" option means that specific information about which orbitals
are retained in the post-SCF calculation will be given in the input file. The
additional input section consists of a line specifying the starting and ending
orbitals to be retained, followed by a blank line. A value of zero indicates the
first or last orbital, depending on where it is used. If the value for the first
orbital is negative (-m), then the highest m orbitals are retained;
if the value for the last orbital is negative (-n), then the highest n
orbitals are frozen. If m is positive and n is omitted, n
defaults to 0. If m is negative and n is omitted, then the highest
|m| occupied and lowest |m| virtual orbitals are retained.
are some examples for a calculation on C4H4:
is equivalent to Full.
5,0 freezes the 4 core orbitals and
keeps all virtual orbitals (equivalent to FC if the basis has a single
5,-4 freezes the four core orbitals and the highest
four virtual orbitals. This is the appropriate frozen-core for a basis with a
6,22 retains orbitals 6 through 22 in the
post-SCF. For example, since C4H4 has 28 electrons, if this
is a closed shell calculation, there will be 14 occupied orbitals, 5 of which
will be frozen, so the post-SCF calculation will involve 9 occupied orbitals (orbitals
6-14) and 8 virtual orbitals (orbitals 15-22).
-6 retains orbitals
9 through 20.
ReadWindow is a synonym for RW.
Performs the same function as the ReadWindow option, but takes its input
as parameters in the route section rather than from the input stream.
The window read in during a previous job is recovered from the checkpoint file.
Causes a list of orbitals to freeze (omit from post-SCF
calculations) to be read from the input stream, terminated by a blank line. Two
lists are read for unrestricted calculations. A range of orbitals can be specified,
e.g.: 2 7-10 14