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

[Gerald Knizia]

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