# direct vs. in-core calculations

*From*: Kevin Moore <kmoore |-at-| ncsc.org>
*Subject*: direct vs. in-core calculations
*Date*: Thu, 29 Apr 93 11:22:34 EDT

One other point that is worth making is that even if you are performing
the calculation with the 5 pure d functions, gaussian is doing the integral
calculation using the 6 cartesian d functions and then performing a
transformation. The default number of d functions varies with the basis
set, so 6-31G* uses the cartesian set by default while 6-311G* uses the
pure set by default (has to do with how the basis set was originally
generated). For a 6-311G** calculation on benzene, if you assume 5d, then
you will come up with N=144 rather than N=150. This would put your projection
at 54.5Mw rather than the actual 64.1Mw (a large difference).
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|| Kevin Moore North Carolina Supercomputing Center ||
|| Scientific Support Analyst 3021 Cornwallis Rd. ||
|| (919) 248-1179 Research Triangle Park, NC 27709 ||
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