From JAMES- at -unca.edu Thu Dec 8 15:18:29 1994 Received: from uncavx.unca.edu for JAMES ":at:" unca.edu by www.ccl.net (8.6.9/930601.1506) id OAA14675; Thu, 8 Dec 1994 14:27:46 -0500 Received: from uncavx.unca.edu by uncavx.unca.edu (PMDF V4.3-8 #5911) id <01HKEIFDSG3K051479 $#at#$ uncavx.unca.edu>; Thu, 8 Dec 1994 14:27:18 EST Date: Thu, 08 Dec 1994 14:27:17 -0500 (EST) From: "Charles G. James" Subject: Z matrix to cartesian coord. Question To: chemistry _-at-_)ccl.net Message-id: <01HKEIFDUL9E051479: at :uncavx.unca.edu> Organization: University of North Carolina at Asheville X-VMS-To: IN%"chemistry -A_T- ccl.net" MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Content-transfer-encoding: 7BIT I do not mean this as an attack upon anyone or anything. However this relates to information I have to pass on to undergraduates in reference to computational chemistry. Just this week someone on this mailing list asked for a way to get 10-15 (significant?) digits, after the komma(decimal), Cartesian coordinates for a Ih symmetry molecule from the z matrix of a Gaussian 92 program. Are we at the stage where that many significant digits are given by any computational chemistry method? Are we at the stage where that many significant digits are obtainable by any physical method used to measure structure? I am still warning undergraduates to beware of the number of digits which can appear in calculations not connected to their measurements or their original input. Can I now say there are ways out there to get precision only formerly dreamed by spectroscopist? Are there ways to get structural parameters to this precision? Charles G. James, Jr. Assoc. Professor of Chemistry Dept. of Chemistry, University of North Carolina at Asheville Asheville, NC 28804-3299, USA Phone: (704)251-6443 FAX: (704)251-6041 E-mail: james # - at - # unca.edu