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Re: Peroidic Table (was exclusion principle which was electrons)

Yes Chuck, fibbing.

Calibration against known facts is a central feature of the 'ab initio' QM
approaches. Basis sets (ground state energy etc) in are judiciously
(arbitrarily) chosen to match the observed real world, and then applied to
making predictions. This applies to all computational methods to which John
Denker has referred me in this thread. The question as to why the 4s orbital
is filled before the 3d has been approached by such methodology. This does
not qualify as an ab initio, because it requires a rear view mirror on the
world to work out what's ahead, ie. it's a form of extrapolation.

I again insist that an ab initio answer to the 4s/3d question hasn't been
done by physics. We await the solution for each element to the
multiple-electron Schrödinger equation. As I suggested, a Nobel prize lies
waiting.



----- Original Message -----
From: "Chuck Britton" <britton@NCSSM.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Sunday, November 16, 2003 5:20 AM
Subject: Re: Peroidic Table (was exclusion principle which was electrons)


Fibbing isn't the word that usually is used - but it might as WELL be.

A grad school colleague of mine was doing 'ab initio' calculations on
the alkali metals in the '70's. He was with the group that John
Slater formed and led at U of Florida. Final Defence comes around and
his result is challenged because they don't agree with the 'ab
initio' results from MIT. Some months later he uncovered the
'arbitrariness' of setting the ground state energy (by MIT) to agree
best with experimental results.

There is 'ab initio' and then there is 'ab initio'.

(ONLY mathematics can prove stuff and THAT depends on carefully noted
assumptions)


At 11:22 AM -0500 11/15/03, John S. Denker wrote:

So all these guys who write papers that talk about "ab initio"
calculations are fibbing?
e.g. http://www.chm.bris.ac.uk/pt/allan/Research/poster/poster.html
http://content.aip.org/JCPSA6/v91/i11/7011_1.html
http://content.aip.org/JCPSA6/v111/i23/10436_1.html
etc.

I found those and 3000 others via

http://www.google.com/search?q=hartree-fock+ab-initio+transition-metal


--
Chuck Britton Education is what is left
when
britton@ncssm.edu you have forgotten everything
North Carolina School of Science & Math you learned in school.
(919) 416-2762 Albert Einstein,
1936