# [molpro-user] Spectroscopic parameters and plotting ???

Łukasz Miądowicz l.miadowicz at gmail.com
Wed Dec 1 22:07:47 GMT 2010

```Hi!

Tnx Gerald for answer, you help me a lot.

I have another question:

If I made my calculations earlier and I have my energies calculated for a
certain dist ( I have my resaults so that I can e.g plot my potential energy
curve) can I put my result to DIATOMIC procedure to find spectroscopic
parameters ?

Or I have to put my calculations from the beginning and put DIATOMIC
procedure just as you did?

I'm considering whether DIATOMIC procedure is independent of making the
calculations on the flow.

I'm thinking of having a table of results (calculated earlier) and you run
molpro only for analyzing result in the term of finding spectroscopic
parameters.

Making all the calculations from the beginning costs a lot of time...

Tnx

Lukas

W dniu 23 listopada 2010 09:29 użytkownik Gerald Knizia <
knizia at theochem.uni-stuttgart.de> napisał:

> On Tuesday 23 November 2010 03:49, Łukasz Miądowicz wrote:
> > 1) Can any one POST a working example how to calculate spectroscopic
> > parameters with MOLPRO ?
>
> Yup:
>
> ---
> memory,50,m;
>
> r0 = 0.91680 ang
> redm = 0.95705545 ! reduced mass
>
> ! make distances from -18%..+30% of equilibrium bond length
> N = 9
> rmin = 0.82 * r0
> rmax = 1.3 * r0
> do i = 0,N-1
>   dist(1+i) = rmin * ((1.0*i)/N) + rmax * ((1.0*(N-1-i))/N)
> end do
>
> basis=avtz
>
> gthresh,energy=1e-8
>
> do i = 1,N
>   r = dist(i)
>   geometry={F; H,F,r}
>   {rhf; accu,16}
>   EHF(i) = ENERGY
>
>   {ccsd(t)-f12b}
>   E(i) = ENERGY
> end do
>
> {table,dist,ehf,e; diatomic,degree=8,MASS=redm}
> ---
>
> > 2) Which spectroscopic parameters does MOLPRO calculate?
>
> Dunham parameters (r_e, B_e, alpha_e, omega_e, we xe, ..).
> The most useful ones are probably the equilibrium distance, the harmonic
> frequency (we) and the anharmonicity parameter (we xe).
>
> > 3) I found DIATOMIC function [1] starting from which version it's
> available
>
> Sorry, I don't know. But I've also not been aware of its existence (in
> Molpro)
> until very recently. This polfit program also existed as an external
> program,
> which was usually used I guess.
> --
> Gerald Knizia
>

--
Department of Theoretical Physics and Quantum Informatics
Faculty of Applied Physics and Mathematics
Gdansk University of Technology
ul. Gabriela Narutowicza 11/12
80-233 Gdansk, Poland
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