CCL:G: EPR g-tensor with Gaussian

 Sent to CCL by: Victor Nemykin [victor_nemykin*_*yahoo.com]
 Hello Silviu:
 You just need to add "nmr" to the Gaussian input line. As a result,
 you
 will have all g-tenzors printed in the NMR part of output file, while
 including "prop" keyword will allow you to get hyperfine coupling
 constants (both Fermi contact term and anisotropic part) in the
 "Properties" part of the output file. From the best of my knowledge,
 both EPR-II and EPR-III basis sets are not supporting Fe. I would
 recommend to use Wachter's basis set (from my experience "Wachter's+f"
 basis set gives a slightly better results as compared to "Wachter's"
 basis set, designated as 6-311+G, implimented into Gaussian) for the
 small-to-intermediate size molecules and DGauss DZVP basis set
 (designated as DGDZVP in Gaussian) for the intermediate-to-large size
 molecules. Next thing to worry about is uncontraction of the s-part of
 the basis set, which is (at least from my experience) bring a dramatic
 improvement of the calculated Fermi contact term values. Such
 uncontraction, however, comes with the computational cost: you have to
 use a better integration grid (i.e. Grid=250770) in order to avoid
 integration instability. Other than these suggestions, please have a
 look into Frank Neese's papers on calculation of the EPR parameters for
 numerous iron complexes.
 Best,
 Victor
 --- "Silviu Zilberman silviu]_[Princeton.EDU"
 <owner-chemistry]![ccl.net>
 wrote:
 > Sent to CCL by: Silviu Zilberman [silviu]~[Princeton.EDU]
 > Dear All,
 >
 > I would like to do some calculations of EPR g-tensor with Gaussian03,
 >
 > for some Fe complexes. I found the Gaussian manual somewhat unclear.
 > It
 > states that using Prop EPR one can get the hyperfine coupling
 > constants,
 > but it's not clear to me how to get the g-tensor.
 >
 > I would like to know what are the keywords and options that control
 > the
 > EPR g-tensor calculation. In addition I would appreciate comments on
 > the
 > proper basis set for these calculations? I found basis sets called
 > EPR-II and EPR-III, which sound like a natural choice. Are these
 > basis
 > sets suitable for Fe complexes?
 >
 > Thanks, Silviu.
 >
 >
 >
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 >
 *****
 Dr. Victor N.Nemykin
 e-mail: victor_nemykin]![yahoo.com
 *****
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