From chemistry-request@server.ccl.net Fri Jan 5 20:42:56 2001 Received: from mailcity.com (fes-qout.whowhere.com [209.185.123.96]) by server.ccl.net (8.8.7/8.8.7) with SMTP id UAA20642 for ; Fri, 5 Jan 2001 20:42:55 -0500 Received: from Unknown/Local ([?.?.?.?]) by mailcity.com; Fri Jan 5 17:14:34 2001 To: CHEMISTRY@ccl.net Date: Fri, 05 Jan 2001 17:14:34 -0800 From: "andri fitriyadi" Message-ID: Mime-Version: 1.0 X-Sent-Mail: off Reply-To: afiet@lycos.com X-Mailer: MailCity Service Subject: Potential Energy function for PVDF X-Sender-Ip: 167.205.22.123 Organization: Lycos Communications (http://comm.lycos.com:80) Content-Type: text/plain; charset=us-ascii Content-Language: en Content-Transfer-Encoding: 7bit Dear CCL mailist members ! I want to calculate potential energy function in PVDF with molecular mechanics approach. I will calculate the energy in two term : steric and electrostatic term. I get some problems , i.e : 1. In steric term I will use a group of non-bonded pairwase potential energy function that suggested by DeSantis. a b c Potensial C  C 3,012 x 10^5 0 327,2 P = a/r^12  c/r^6 F  F 1,057 x 10^5 4,608 125,1 P = ae^-br  c/r^6 H  H 3,716 x 10^3 3,071 89,52 P = ae^-br  c/r^6 C  F 1,785 x 10^5 2,304 202,2 P = (ae^-br  c)/r^6 C  H 3,347 x 10^4 1,535 589,0 P = (ae^-br  c)r^6 F  H 1,982 x 10^4 3,839 497,6 P = ae-b^r  c/r^6 My questions are : a. Why DeSantis use Lenard-Jones Potential in C-C interaction but Buckingham potential in F-F,H-H, and F-H interactions ? Why must be different ? b. I have never seen equation both of C-F and C-H interaction ? How can I derive it with classical mechanics approach ? 2. In electrostatic term, I get a problem to determine the partial charges of QH, QF, QH2 and QF2. My refference suggested to use Del Re Method. What's Del Re Method ? Where can I learn this method ? Thank You for Your Help ! Best Regards Andri Fitriyadi Department of Physics Conjugated Organic Materials and Superconductor Laboratory Institut Teknologi Bandung West Java, Indonesia my another e-mail : afiet102@cyberlib.itb.ac.id Get FREE Email/Voicemail with 15MB at Lycos Communications at http://comm.lycos.com From chemistry-request@server.ccl.net Sat Jan 6 07:16:43 2001 Received: from smtp1.dti.ne.jp (smtp1.dti.ne.jp [202.216.228.36]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id HAA23825 for ; Sat, 6 Jan 2001 07:16:42 -0500 Received: from oemcomputer (PPP289.fukuoka-ip.dti.ne.jp [211.132.93.39]) by smtp1.dti.ne.jp (8.9.3/3.7W) with SMTP id VAA11491 for ; Sat, 6 Jan 2001 21:16:29 +0900 (JST) Message-ID: <009301c077da$4e18d500$3025fbd2@oemcomputer> From: "T.Tsuru" To: "CCL, Post" Subject: Polymer Designing... with MO or DFT --- SUMMARY Date: Sat, 6 Jan 2001 21:15:05 +0900 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Hello ! CCLers Last month(last century!), I sent a question as follows: > I'm looking for polymer designing methods which are using semi-empirical > or ab-initio MO, and or DFT. Especially I would like to design 1) conductive > polymer, 2) ferroelectric polymer. > > If you know the articles or Web sites which are describing the method of > them, please let me know. Then I received very useful and helpful replys. I summarize and introduce them. If you have any question of them, please let me know. Thanks a lot ! ---- 1)from Doug Smith ----- A few years ago I ran a small business that did exactly what you are asking about. Somre references: Douglas A. Smith, Charles W. Ulmer, II, Bobby G. Sumpter, and Donald W. Noid, "Rational Design of Polymeric Materials Using Neural Networks," Scientific Computing & Automation 1997, 14(9), 51 - 55. Charles W. Ulmer, II, Douglas A. Smith, Bobby G. Sumpter, and Donald W. Noid, "Computational Neural Networks and the Rational Design of Polymeric Materials: The Next Generation Polycarbonates," J. Comput. Theo. Poly. Sci., 1998, 8, 311 - 321. We also received a U.S. Patent, # 5,629,404, in 1997 for the materials designed by molecular modeling ---- 2)from Stephan Irle ---- During my PhD thesis I studied polythiohenes and poly(p-phenyl) dope with Li and Cl atoms at the ab initio and DFT level of theory. You can find more information at: http://euch4m.chem.emory.edu/~irle/Polaron/index.html and four papers that I wrote at http://euch4m.chem.emory.edu/~irle/cv_e.html#Publications --------------------------------------------------- Telkuni Tsuru telkuni@venus.dti.ne.jp Representative of Research Information Service of Molecular/with Knowledge Management? Bunshi Gijyutu ---------------------------------------------------