Subject: RELATIVITY IN COMP CHEM

From: "E. Lewars" <[email-masked]>
Date: Tue, 9 Sep 1997 11:01:16 -0400 (EDT)

1997  Sept 9

Hello,

Concerning the importance of the theory of relativity in computational
chemistry:

1)  Are there cases where the Dirac-Fock equation, rather than the Schroedinger
    equation, should be used?
2)  To what extent are the effective core potentials of ab initio
    calculations derived empirically, to fit experiment, rather than
    theoretically?
3)  Where should you start using effective core potentials to simulate
    relativistic effects --at which element does the error start becoming
    significant (somewhere around element 33 to 37, I suspect--As, Se, Br,
    Kr, Rb)?

    Thanks

           E. Lewars
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