Subject: QSPR stability: Cross-valid. coef

From: Didier MATHIEU <[email-masked]>
Date: Tue, 23 Feb 1999 18:35:46 +0100

Dear CCLers,

I am trying to estimate sublimation enthalpies in terms of a short-range
term based on atomic surface tensions (with an additional correction for
H-bonds) plus an electrostatic term.

I got a fairly good fit for some ~200 molecules, while 8 parameters
empirically adjusted.
Now I would like to estimate the stability of the model equation wrt the
training set.
I read in literature (e.g. Katritzky et al. J.Chem.Inf.Commput.Sci.38,
840 (1998)) that a measure of this stability is given by a so-called
"cross-validated correlation coefficient".

I would be grateful if somebody could give me the exact definition of
this coefficient or points to references.

BTW, I guess some readers of this request have experience in
interpolating experimental data through QSPR. So far I got all data from
the NIST Chemistry WebBook, which is a bit cumbersome, especially with a
slow access to the web from outside the laboratory.
Does anybody know similar extensive compilations of thermodynamical
data, on paper or preferably CD-ROM ? I am only aware of the CRC
Chemistry Handbook and J.Chem.Phys.Ref.Data.

Thanks.

-- 
Didier MATHIEU
CEA - Le Ripault, BP 16
37260 Monts (France)
Tel. 33(0)2.47.34.41.85