Subject: Is ab initio semiempirical ?

From: "Dr. Jan Hrusak" <[email-masked]>
Date: Tue, 16 May 1995 10:54:11 +0100

In general I do not like such philosophical discussions,  but on the other 
hand I would like to stress my opinion to this particular problem. I 
think there is no reason for DFT to enter a claim to be called ab 
initio. Since in my wiev just very few ab initio calculations are 
realy  "first principle" calculations. First of all, ab initio is 
just an approximation to solution of the Schroedinger equation.
There is usually an (arbitrary or not) chosen a  basis set (parameter set?) 
for a given atom. Further, in many of the ab initio codes not 
all the integrals are evaluated in course of the calculation. 
(neglecting small int., cuttoff criteria are set etc.)
Thus "ab initio" in a strong sense is just an terminus 
technicus describing a given technique, which is more or less non 
empirical.

Jan

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