CCL:G: G03-SCRF calculations with hexane

 Sent to CCL by: "David  Hose" [Anthrax_brothers|-|hotmail.com]
 Marcel,
 Thanks for the tip about calculating the optical dielectric constant from the
 refractive index.  I'm
 sure that I'll be using that very frequently.
 Andy,
 Thanks for the parameters for DMF and the tip about the OFac and RMin parameters
 when PCM
 calculation run amuck.
 Many thanks.
 Regards,
 Dave.
 Hi David, Jose,
 I had a similar problem with ADF, where the optical dielectric
 constant (EPSINF) was not directly
 given in the CRC handbook. However, then I asked around, and I got
 this helpful answer:
 > The optical dielectric constant is directly related to the
 > refractive index, eps_op = n^2.
 > The refractive index should be in the Handbook.
 On Mar 10, 2008, at 10:12 PM, David Hose anthrax_brothers_-
 _hotmail.com wrote:
 >
 > Sent to CCL by: "David Hose" [anthrax_brothers|*|hotmail.com]
 > Jose,
 >
 > Like you, I'm also trying to run PCM calculations in non-standard
 > solvents. Since my original post
 > I've been digging through the literature trying to find answers for
 > DMF and NMP.
 >
 > The Gaussian manual states that if you don't state values explicit
 > values for EPS, RSOLV, DENSITY
 > and EPSINF, then they default to the values for water (http-:-//
 > www.gaussian.com/g_ur/k_scrf.htm).
 > So just specifying the dielectric constant isn't enough. You could
 > just go with the values for
 > heptane (I doubt that it will make much of a difference).
 >
 > In the course of chasing down values for the solvent radii, I came
 > across an interesting paper by E.S. Boes et al., Chemical Physics,
 > 2006, 331, 142158
 > (dx.doi.org/10.1016/j.chemphys.2006.08.028) They were looking at
 > the parameterisation of IEF-
 > PCM calculations of mono-anions in acetonitrile and DMF. The paper
 > cites Abraham and Liszi (J.
 > Chem. Soc. Faraday Trans. 1978, 74, 1604.) for the molecular radii
 > of the solvents which in turn
 > states that the radii of the solvents are calculated from the
 > Stearn - Eyring equation (A. E. Stearn
 > and H. Eyring. J. Chem. Phys., 1937, 5, 113).
 >
 > r=(V/8*Na)^(1/3)
 >
 > where r is the solvent radius (Angstroms), V is solvent molar
 > volume (m3 / mol), and Na is
 > Avogadro's constant.
 >
 > The EPSINV values are causing me a headache. Whilst the CRC Rubber
 > Handbook of Chemistry and
 > Physics has loads of information about the dielectric constant of
 > water at different temperatures,
 > pressures and frequencies, I can't find values for DMF and NMP. In
 > your case, I would either use the
 > value quoted for heptane (the output contains the values used in
 > the PCM calculation) or use the
 > default value for water which from memory is about 1 - 2
 > (personally I'd use the value for heptane
 > in the absence of any better data).
 >
 > Hope that helps.
 >
 > Regards,
 >
 > Dave.
 >
 >
 > Sent to CCL by: "Jose P. Ceron" [jpceron(_)um.es]
 > Dear all,
 > I need to include solvent effects in TDDFT calculations to compare
 > my results with experimental
 > data. The problem is that the UV-Vis spectra are made in hexane and
 > this solvent is not define in
 > Gaussian.
 > I know EPS, RSOLV, DENSITY and EPSINF keyword can be used with PCM
 > model,
 > but is it enough to specify EPS(hexane)=2.0?
 > Any suggestion will be welcome!!
 > Thanks in advanced,
 > Jose
 >
 > -----------------------
 > Jose P. Ceron
 > University of Murcia
 >
 >
 >
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 >
 ===================================
 dr. Marcel Swart
 ICREA researcher at
 Institut de Qumica Computacional
 Universitat de Girona
 Parc Cientfic i Tecnolgic
 Edifici Jaume Casademont (despatx A-27)
 Pic de Peguera 15
 17003 Girona
 Catalunya (Spain)
 tel
 +34-972-183240
 fax
 +34-972-183241
 e-mail
 marcel.swart**icrea.es
 marcel.swart**udg.edu
 web
 http://www.icrea.es/pag.asp?id=Marcel.Swart
 http://iqc.udg.edu/~marcel
 ===================================