CCL: SV: Fitting IRC data to a polynomial function

Dear Jens,

It looks like  asymmetric  double minimum. I have tried to fit it to a simple quartic  potential but the fit isn't good.



On Mon, Sep 28, 2015 at 2:12 AM, Jens Spanget-Larsen spanget _ <owner-chemistry]~[> wrote:

Dear Fred;


If your are investigating a symmetrical double minimum potential, you may consider a simple quartic potential with a quadratic barrier. The numerical solutions to the eigenvalue problem have been tabulated by Jaan Laane:


Mvh, Jens >--<



  JENS SPANGET-LARSEN         Office:      +45 4674 2710

  Dept. of Science            Fax:         +45 4674 3011

  Roskilde University         Mobile:      +45 2320 6246

  P.O.Box 260                 E-Mail:     spanget *

  DK-4000 Roskilde, Denmark



Fra: * [ *] på vegne af Fredrick Mutunga [owner-chemistry *]
Sendt: 28. september 2015 01:49
Til: Jens Spanget-Larsen
Emne: CCL: Fitting IRC data to a polynomial function

Hello  Fellow CCL Members,
 I want to fit an IRC data points attached to a polynomial form to get a
 potential function which I intent to use in calculating WKB barrier penetration
 integral. I have tried several simple polynomials forms up to 5th order
 including some exponentials using Mathematica's NonLinearModelFit but non of
 them seem to work!
 Does any of you guys have an idea what kind of form I should be trying?