From chemistry-request at.at server.ccl.net Mon Feb 28 01:38:56 2000 Received: from mail.xnet.com (quake.xnet.com [198.147.221.67]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id BAA14070 for ; Mon, 28 Feb 2000 01:38:55 -0500 Received: from [205.243.139.24] (chamot.chamotlabs.com [205.243.139.24]) by mail.xnet.com (8.9.3+Sun/XNet-3.0R) with ESMTP id AAA25643; Mon, 28 Feb 2000 00:38:45 -0600 (CST) X-Sender: chamot # - at - # mail.xnet.com (Unverified) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 28 Feb 2000 00:42:07 -0600 To: Computational Chemistry List From: Ernest Chamot Subject: CCL:The "birth-year" of computational chemistry? Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by server.ccl.net id BAA14071 This discussion has been interesting because, as Dominic Ryan pointed out: >. . . . It depends of course on just >what you call computational chemistry. Use of the term to mean: the ability to describe a chemical or chemical process mathematically (Theoretical Chemistry? Pople's & Ryan's point of view?), vs. actually carrying out the necessary computation (Calculational Chemistry?) The use of computers by chemists (analyzing data, etc.; Computers in Chemistry?) vs. modeling a chemical or chemical process with the computer (Molecular Modeling?). Use of "Computer" in the original, more general sense (a machine that returns a numerical result; Marchesa's point of view?), vs. a more modern meaning (understood to refer to electronic, digital computers?) Etc. IMHO, what makes Computational Chemistry distinct, is that our chemical theories have been implemented in software, and computer hardware has developed that can run that software, to the point that it is practical to routinely APPLY theory to accurately model molecular structure and chemical processes, and to calculate numerical results which were previously only available experimentally. So from that point of view, the "Birth" of Computational Chemistry must be when these theories _started_ being converted into software and run on the type of computer hardware that _ultimately_ became fast enough to _routinely_ model chemistry. So I think Lingran's second question comes close to defining the birth: >2. Who wrote the first quantum chemistry program? The only thing I would add, is that since only electronic, digital computers have been developed to be programmable and fast enough to routinely do these calculations, I would say the birth year is the year that someone first coded and ran a quantum chemistry (or other molecular modeling) program on an electronic, digital computer. The worlds first electronic, digital computer, ENIAC (Electronic Numeric Integrating Automatic Computer), was constructed at the University of Pennsylvania in 1945, this sets an early limit for the birth of Computational Chemistry. With this point of view in mind, I have some inside information (albeit second-hand) about the early days, that is relevant. I have a close relationship with one of the programming pioneers at Argonne National Laboratories. Cynthia Chamot (yes, this is my Mother, and I'm quite proud of her) was one of the early programmers hired by Argonne to program the third, all electronic, digital computer ever built, AVIDAC. AVIDAC (Argonne's Version of the Institute's Digital Automatic Computer) was constructed around 1950, only 5 years after ENIAC. (Argonne's second computer, by the way, was named "George.") She recalls working as part of a team with several others (including Ruth Freshour & Gerry Duffy) in the Applied Math Division, to develop code for John Weil in the Chemistry Division, by 1956. She specifically remembers the need for part of the code to find eigenvalues and invert 13x13 matrices with only 512 "words" (not K) of memory to work in! She isn't sure whether this was a QM calculation, but it looks like Computational Chemistry had started at Argonne sometime between 1950 and 1956. Prior to that, the military used computers on the Atomic Bomb project, as Richard Gillian mentioned: >I seem to recall, that Monte Carlo methods invented during the >Atom Bomb project in the 40's may have been the first electronic >computer calculations on condensed matter, although they may not qualify as >chemistry. I remember a facinating talk by W. Wood (Los Alamos) at a computer I know one of the earliest uses was to analyze the probability of one nuclear reaction triggering multiple nuclear reactions, to determine exactly what constituted a critical mass. Is this the 'Monte Carlo" calculation referred to in Gillian's reference? If so, I would consider this a Computational Physics or statistical computation rather than Computational Chemistry. If it really is a Chemistry code, then the birth of Computational Chemistry may be before 1950: as early as 1945. EC --- Ernest Chamot Chamot Laboratories, Inc. 530 E. Hillside Rd. Naperville, Illinois 60540 (630)637-1559 echamot.,at,.chamotlabs.com http://www.chamotlabs.com/cl