Next: Bibliography
Up: DeterminantBased CI
Previous: Olsen's Full CI Equations
It is easy to vectorize the formation of
since
each element
can be written as
independent of
apart from multiplication by a factor
.
The vectorized algorithm for the
evaluation of ,
adapted from reference [16],
appears in Figure 5. An analogous algorithm
can be used to obtain .
However, we can also obtain
for M_{s} = 0 states by

(tex2html_deferredtex2html_deferred6.tex2html_deferred29 _2(I_, I_) = (1)^S _1(I_, I_)
) 
as proven by Olsen and coworkers [16].
Figure:
Vectorized Algorithm for .

A fairly straightforward algorithm for evaluating
is
presented in Figure 6. The vectorized
algorithm for the evaluation of
is presented in
Figure 7. This algorithm makes use of a
gather and scatter operation to avoid indirect addressing.
Figure:
Simple Algorithm for .

Figure:
Vectorized Algorithm for .

For M_{s}=0, an improvement to the
algorithm can be made
by utilizing an identity similar to equation (6.31).
The ijklth component of
is related to the klijth
component via

(tex2html_deferredtex2html_deferred6.tex2html_deferred30_3^ijkl(I_, I_) =
(1)^S _1^klij(I_, I_)
) 
Next: Bibliography
Up: DeterminantBased CI
Previous: Olsen's Full CI Equations
C. David Sherrill
20000418