From owner-chemistry%!at!%ccl.net Thu Feb 14 08:34:00 2008 From: "zborowsk^chemia.uj.edu.pl" To: CCL Subject: CCL: Scaling of Raman Frequencies Message-Id: <-36290-080214082957-30363-ar9tBHsI5oWy8YJEwBLwzw{}server.ccl.net> X-Original-From: zborowsk_+_chemia.uj.edu.pl Content-Transfer-Encoding: 8bit Content-Type: text/plain;charset=iso-8859-2 Date: Thu, 14 Feb 2008 14:29:26 +0100 (CET) MIME-Version: 1.0 Sent to CCL by: zborowsk[#]chemia.uj.edu.pl > I have a few questions concerning the calculation of raman frequencies. > The > first is, should one consider the IR scaling factors to be valid for > Raman? > Raman is essentially an emission phenomenon while IR frequencies are an > abosorbance phenomenon. > I do not understand where is the problem (if we consider the frequencies scaling, not intensities)? It is true that Raman and IR are based on two (very) different phenomena. But the frequencies of normal modes are the same and they do not depend on emission or absorption. There is no thing like "scaling factor for IR frequencies". You scale frequencies of normal modes, not IR frequencies or Raman frequencies > My second question is, if Raman frequencies should be scaled, should Raman > frequencies determined by incorporation of solvent effects also be scaled? > > Any thoughts on this are welcome. > > > Mark > -- Krzysztof Zborowski Faculty of Chemistry Jagiellonian University 3 Ingardena Street 30-060 Krakow Poland phone: +48(12)632-4888 ext. 2064 or 2067 fax: +48(12)634-05-15 email: zborowsk]*[chemia.uj.edu.pl ICQ 158385743 gg 3817259 skype kzys70