The calculation starts with generating the configuration state functions
using lsgen and lsreduce, which are explained in ,
and
.
The first choice is the decision of the model to be used for
generating expansions. In this example, the wave function expansions
were obtained from orbital sets of increasing size characterized by
their maximum quantum number. For orbital sets with
or
, these
were obtained, by single (S) and double (D) excitations from a
multi-reference set, treating
as a common closed core. The
multi-reference set contained all configurations
and
. Only those configuration states from SD
excitations which interacted with at least one member of the multi-reference
set were retained. To these expansions
were added all configuration states of the form
at the
stage and then
at the
stage.
In this notation
implies any combination of
orbitals
which, when coupled to two of the orbitals in the last orbital set,
yields the required term and parity. All configuration files, including
the multi-reference sets are located in the directory atsp2K/files_c.
The configuration lists have *.c suffix, the reference lists are
prefixed with mrlist.