From owner-chemistry%!at!%ccl.net Mon Mar 23 19:29:00 2015 From: "zborowsk zborowsk^chemia.uj.edu.pl" To: CCL Subject: CCL:G: Gaussian IR frequency calculation Message-Id: <-51177-150323183440-29086-gvYzmRPICXn7A6GVaHdnhA,server.ccl.net> X-Original-From: zborowsk Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8; format=flowed Date: Mon, 23 Mar 2015 23:34:30 +0100 MIME-Version: 1.0 Sent to CCL by: zborowsk [zborowsk^chemia.uj.edu.pl] W dniu 2015-03-23 19:26, ggotelli()kaliumtech.com napisał(a): > Sent to CCL by: [ggotelli[]kaliumtech.com] > Thank you all for your help! > I'll condense all my notes in the same mail. > > Krzysztof , yes I observed the difference in the whole spectrum. Well, something strange. 300-400 cm-1 difference between theory and experiment around 3000 cm-1 and also around 100 cm-1?? By the way, do you have positive or negative (imaginary) frequencies around 100??? > > Serdar, the molecule that I 'm trying to calculate and where I have > the > differences is a dimer derived from dilactide. To estimate a scaling > factor > my reference molecule is dilactide in itself, which in turn has > little > differences between the calculated spectrum and the real one, > depending on > the peaks. > > André, thanks for the scaling factor reference. > > Stent, the polymer spectrum was made with an ATR device and without > solvent. > Because of this all calculations have done in vacuum. > > Robert, thanks for all your comments, they made me realize that my > error was > trying to adjust a dimer spectrum to a polymer spectrum, what are, of > course, very different things. Although the dimer peaks are displaced > with > respect to those of the polymer, it can be seen from the GView > animation > that they correspond to what is expected, beyond the displacement > involved. > > Regards! > Gustavo Gotelli > Polymer Synthesis > Pharmaceutical Technology Department > Faculty of Pharmacy and Biochemistry > Buenos Aires University > Argentina > > -----Mensaje original----- > De: owner-chemistry+ggotelli==kaliumtech.com a ccl.net > [mailto:owner-chemistry+ggotelli==kaliumtech.com a ccl.net] En nombre > de > Víctor Luaña Cabal victor^^fluor.quimica.uniovi.es > Enviado el: sábado, 21 de marzo de 2015 21:16 > Para: Gotelli, Gustavo A > Asunto: CCL: Gaussian IR frequency calculation > > > Sent to CCL by: =?iso-8859-1?Q?V=EDctor_Lua=F1a?= Cabal > [victor]|[fluor.quimica.uniovi.es] > On Sat, Mar 21, 2015 at 05:56:44PM -0400, Robert Molt > r.molt.chemical.physics],[gmail.com wrote: >> >> Sent to CCL by: Robert Molt [r.molt.chemical.physics---gmail.com] >> Moreover, you are using the B3LYP functional. It has limited >> accuracy, >> depending on the system specifics. If it is a multi-reference >> problem, >> great care is necessary. >> >> Also note that you can only compare the TOTAL spectrum, not any one >> peak. > > Robert, > > 1) Let me take your highly correct advise to remember to the newest > generations that the role on computational chemistry is not being > able to reproduce the number of the experiment. > > 2) The experiment helps in modulating our calculations, and the final > objective is a perfect reprodution of the experiment. > > 3) But the reason is not substituting experiments. The reason is that > in the processs of mimicking it we learn the rules that govern > Nature. > > 4) There are too many questions in this forum that tend to ignore > this rule and it is important to remember it again and again. > > Best regards, > Dr. Víctor Luaña > -- > . . "The hardest part in solving a problem is recognizing > / `' \ its existence. Learning the causes CAN be the road to > /(o)(o)\ the solution." > /`. \/ .'\ -- ¿? > / '`'` \ "Lo mediocre es peor que lo bueno, pero también es peor > | \'`'`/ | que lo malo, porque la mediocridad no es un grado, es > una | > |'`'`| | actitud" > \/`'`'`'\/ -- Jorge Wasenberg, 2015 > > ===(((==)))==================================+========================= > ! Dr.Víctor Luaña ! Mediocre is worse than > ! Departamento de Química Física y Analítica ! good, but it is also ! > Universidad de Oviedo, 33006-Oviedo, Spain ! worse than bad, because > ! e-mail: victor-#-fluor.quimica.uniovi.es ! mediocrity is not a > grade, > ! phone: +34-985-103491 fax: +34-985-103125 ! it is an attitude > +--------------------------------------------+ > GroupPage : http://azufre.quimica.uniovi.es/ (being > > reworked)http://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt > > > -= This is automatically added to each message by the mailing script > =- > To recover the email address of the author of the message, please > change> Conferences: > http://server.ccl.net/chemistry/announcements/conferences/-- https://www.youtube.com/watch?v=IGyfx3Pmeyk Krzysztof K. Zborowski Faculty of Chemistry Jagiellonian University 3 Ingardena Street 30-060 Krakow Poland phone: +48(12)663-2067 email: zborowsk!=!chemia.uj.edu.pl gg 3817259 skype kzys70 www.chemia.uj.edu.pl/~zborowsk