Subject: F AS PROBLEM ELEMENT; A COULSON QUOTE

From: "E. Lewars" <[email-masked]>
Date: Thu, 26 Nov 1998 15:26:04 -0500 (EST)

1998 Nov 25

Hello,

(1)  Does anyone have any refs to document the view that in ab initio calc's
     F is a problem element--for example, that optimization of fluorine-
     containing molecules does not readily give good geometries (or energies?)?
     I have refs to FOOF and to F2; any instances of other troublesome
     F-containing species would be welcome.

(2)  Someone, I think it may have been Coulson, said, ca. 1952, that calculating
     the energy differenece between two isomers as the difference in their
     computed energies is like weighing the captain by weighing the ship with
     and without him. I would appreciate the reference to this statement.
     [Of course in the 1950's few dreamt that it would ever be possible to
     calculate energy differences to chemical accuracy, at least by ab initio
     methods].

       Thanks
        E. Lewars
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