From kmoore@ncsc.org Thu Apr 29 07:22:34 1993 Date: Thu, 29 Apr 93 11:22:34 EDT From: Kevin Moore Message-Id: <9304291522.AA29633@duck.ncsc.org> To: chemistry@ccl.net Subject: direct vs. in-core calculations 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). ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ || Kevin Moore North Carolina Supercomputing Center || || Scientific Support Analyst 3021 Cornwallis Rd. || || (919) 248-1179 Research Triangle Park, NC 27709 || ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++