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Date: Tue, 14 Nov 95 15:52:09 IST
From: "Moshe Olshansky" <moshe_o -AatT- VNET.IBM.COM>
To: chemistry # - at - # www.ccl.net
Subject: Combining different basis sets


Dear CCL'ers!
We are working on computational aspects of the Hartree-Fock procedure.
For this purpose we would like to have some f-type basis functions
but not too many of them,  while all the basis sets we have either
do not have f functions at all or have too many of them (our trial
molecule contains H C N and O atoms).
Since we are not chemists I would like to ask the following
(possibly very trivial) question:  does it make any sense to combine
two different basis sets (for example,  take a smaller basis set for
H and C and a larger one - containing d and f functions - for N and O)?

Thank you very much and please forgive my ignorance
Moshe Olshansky
IBM Israel Science and Technology
<moshe_o (- at -) vnet.ibm.com>