The new version of the genclf program has the same design as GENCL (see Froese Fischer and Liu [#!FL!#]) but has been extended to arbitrarily-filled f-shells. The latter required some change in notation. The subroutines that changed a lot are the LVAL, SYMB and COUPLD. The rest of the subroutines are either unchanged or the changes are not substantial. The LVAL subroutine is extended with a possibility to convert the symbols O and Q into its corresponding quantum number and in SYMB to convert the quantum numbers 11 and 12 into its corresponding symbol. In the COUPLD subroutine the data blocks containing the term characteristics are enlarged.
Input and output data of the new version are the same as before.
One needs only to take into account that the classification of
terms of the subshell
is more complicated than for
,
,
subshells.
For the classification of
-subshell terms the characteristics (2
+1)
(multiplicity),
(total orbital momentum), and
(seniority) are not
sufficient.
Here we use a notation
for the classification of
an
-subshell.
The
is single character, which corresponds the group
labels
. It is identical to Gaigalas
and Froese Fischer [#!GFa!#] and P5 [#!__5172__method5__5172__!#].
The value
is found in Table 1 of P5 [#!__5173__method5__5173__!#]
where all terms for
-subshells are presented. In most
cases,
appears to be a digit, but since it is a single
character, the single letter
is used instead of the number 10.
While in all the other cases the two-digit numbers n in
file
encode the following
= CHAR(n+ICHAR('0')) (see [#!FL!#]).
For example, the values of the principal quantum number
or multiplicity
may exceed 9. On most systems the list of
integers,
map into the list of characters,
. The CSF list if output to the file cfg.inp.
When -shells are restricted to two electrons, the earlier
LSGEN program may be used [#!lsgen!#]. This program
has been extended to arbitrarily filled f-shells, and is known as
lsgenf but has not been documented. Like LSGEN, the CSF list that
is output is left in clist.out. For simple cases, gencl is
easier to use interactively. Unlike genclf where
on
SUN systems must be entered as
, lsgenf allows the user to
specify
, although the output file will adhere to the proper
convention.
The program maintains an order for the orbitals, determined from the order in which an orbital is first encountered. Thus, with a reference set of 4s(2)3d(1) and an active set of 3d,4s,4p the file cfg.inp will not have orbitals in a consistent ordering. The ordering of orbitals in the reference set, the active set, and the virtual set should always be the same in the sense that one orbital will always appear before or after another. Sometimes this is referred to as the after relation.