From chemistry-request@server.ccl.net Sun Aug 20 00:18:15 2000 Received: from mail-relay-pune.ernet.in (mail-relay-PUNE.ernet.in [202.41.82.35]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id AAA18299 for ; Sun, 20 Aug 2000 00:18:08 -0400 Received: from jivdhan.unipune.ernet.in (mailhub.unipune.ernet.in [196.1.114.31]) by mail-relay-pune.ernet.in (8.9.1/8.9.1) with ESMTP id WAA20735 for ; Sat, 19 Aug 2000 22:44:58 +0530 Received: from chem.unipune.ernet.in (chem.unipune.ernet.in [196.1.114.10]) by jivdhan.unipune.ernet.in (8.9.0/UnipuneMailhubV1.3) with ESMTP id WAA15266; Sat, 19 Aug 2000 22:17:00 +0530 Received: from localhost (gadre@localhost) by chem.unipune.ernet.in (8.8.7/8.8.7) with SMTP id WAA07230; Sat, 19 Aug 2000 22:57:35 +0530 Date: Sat, 19 Aug 2000 22:57:35 +0530 (IST) From: "Prof. Shridhar R. Gadre" To: CHEMISTRY@server.ccl.net cc: CHEMISTRY@osc.ccl.edu.ernet.in Subject: (Large)Molecule properties Message-ID: MIME-Version: 1.0 Content-Type: MULTIPART/REPORT; REPORT-TYPE=delivery-status; BOUNDARY="WAA20657.966704460/mail-relay-pune.ernet.in" Content-ID: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. Send mail to mime@docserver.cac.washington.edu for more info. --WAA20657.966704460/mail-relay-pune.ernet.in Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-ID: Dear Colleages : We have developed a very efficient algorithm to obtain ab initio-qualty molecular electron densities and electrostatic potentials for reasonably large molecules (viz. with more than 500 but less than 1000 atoms including hydrogens). Do you have some test cases of polypeptides, polymers or proteins of this type..where you would like to obtain ab initio quality electron densities or electrostatic potentials? Thanks for your help!......................Shridhar gadre --WAA20657.966704460/mail-relay-pune.ernet.in-- From chemistry-request@server.ccl.net Sun Aug 20 00:18:54 2000 Received: from mail-relay-pune.ernet.in (mail-relay-PUNE.ernet.in [202.41.82.35]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id AAA18308 for ; Sun, 20 Aug 2000 00:18:52 -0400 Received: from jivdhan.unipune.ernet.in (mailhub.unipune.ernet.in [196.1.114.31]) by mail-relay-pune.ernet.in (8.9.1/8.9.1) with ESMTP id SAA19133 for ; Sat, 19 Aug 2000 18:05:10 +0530 Received: from chem.unipune.ernet.in (chem.unipune.ernet.in [196.1.114.10]) by jivdhan.unipune.ernet.in (8.9.0/UnipuneMailhubV1.3) with ESMTP id RAA13978 for ; Sat, 19 Aug 2000 17:37:27 +0530 Received: (from gadre@localhost) by chem.unipune.ernet.in (8.8.7/8.8.7) id SAA06802 for CHEMISTRY@www.ccl.net; Sat, 19 Aug 2000 18:18:18 +0530 Date: Sat, 19 Aug 2000 18:18:18 +0530 From: "Prof. Shridhar R. Gadre" Message-Id: <200008191248.SAA06802@chem.unipune.ernet.in> To: CHEMISTRY@server.ccl.net Subject: Test cases for molecular fragmentation Dear Colleages : We have developed a very efficient algorithm to obtain ab initio-qualty molecular electron densities and electrostatic potentials for reasonably large molecules (viz. with more than 500 but less than 1000 atoms including hydrogens). Do you have some test cases of polypeptides, polymers or proteins of this type..where you would like to obtain ab initio quality electron densities or electrostatic potentials? Thanks for your help!......................Shridhar gadre From chemistry-request@server.ccl.net Sun Aug 20 03:43:35 2000 Received: from ivory.trentu.ca (trentu.ca [192.75.12.103]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id DAA19207 for ; Sun, 20 Aug 2000 03:43:35 -0400 Received: from trentu.ca ([204.225.13.50]) by trentu.ca (PMDF V5.2-32 #29543) with ESMTP id <01JT5T913EOY00007W@trentu.ca> for chemistry@ccl.net; Sat, 19 Aug 2000 16:43:31 EDT Date: Sat, 19 Aug 2000 16:48:07 -0400 From: elewars Subject: DFT: NO ORBITALS, NO WAVEFUNTION To: chemistry@ccl.net Message-id: <399EF287.2FFE7CD2@trentu.ca> MIME-version: 1.0 X-Mailer: Mozilla 4.7 [en] (WinNT; I) Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Accept-Language: en Sat, 2000 Aug 19 Hello, We know that in pure DFT (in contrast to wavefunction theory) there are are no orbitals and there is no wavefunction; the Kohn-Sham orbitals of current practical DFT methods were introduced to make the calculation of the electron density tractable. QUESTIONS (1) An important feature of ab initio (and semiempirical) calculations is that one can visualize the orbitals, particularly the HOMO and LUMO (frontier orbitals) and make chemical deductions. In a _pure_ DFT calculation a question about the shape and energy of these orbitals would be meaningless, right? (2) The Fukui function (R. G. Parr and W. Yang, J Am Chem Soc, 1984, 106, 4049) seems to be always discussed in the context of DFT; yet this function is "a chemical reactivity index in the sense of the frontier-electron theory of reactivity..." (R. G. Parr and W. Yang, "Density-Functional Theory of Atoms and Molecules", Oxford, New York, 1989, p. 101). But in pure DFT theory there are no frontier orbitals. Isn't this strange? (3) If, as has been suggested (Parr and Yang, "Density-Funtional Theory...", p. 53) wave mechanics can be reformulated without the wavefunction concept, what are we to make of the 80-year-old debate in physics and philosophy about the meaning of the wavefunction (wavefunction collapse, Schroedinger's cat, the many-worlds theory of QM, etc, etc, etc; see e.g. "Einstein, Bohr and the Quantum Dilemma", A. Whitaker, Cambridge University Press, Cambridge, 1996, and _many_ other books and papers...). Was this debate a meaningless exercise that would never have occurred if QM had been originally formulated in terms of electron (or more generally, particle) density rather than the wavefunction? Thanks, E. Lewars ====