[molpro-user] CCSD/eom

[Tatiana Korona]

Dear Behnam,

Acetone has a C2v symmetry, i.e. 4 irreps, and you calculated excited states of 
symmetry A1 only.

I repeated the calculations with the modified input:

  hf
  ccsd
  eom,-5.1,-4.2,-4.3,-4.4,trans=2


and got the result:

[tania at gimli runs]$ grep "repeated" acetone.out
    2.1          7.443     0.00064863 spectrum data (repeated)
    3.1          8.457     0.01551765 spectrum data (repeated)
    4.1          8.630     0.04681259 spectrum data (repeated)
    5.1          9.482     0.30440989 spectrum data (repeated)
    1.2          8.588     0.01512075 spectrum data (repeated)
    2.2          9.442     0.01113363 spectrum data (repeated)
    3.2          9.483     0.00151735 spectrum data (repeated)
    4.2         10.570     0.04712754 spectrum data (repeated)
    1.3          6.440     0.03605405 spectrum data (repeated)
    2.3          7.455     0.00177874 spectrum data (repeated)
    3.3          7.994     0.00268525 spectrum data (repeated)
    4.3          8.453     0.03809156 spectrum data (repeated)
    1.4          4.593     0.00000000 spectrum data (repeated)
    2.4          7.338     0.00000000 spectrum data (repeated)
    3.4          8.429     0.00000000 spectrum data (repeated)
    4.4          8.648     0.00000000 spectrum data (repeated)

so you see that all excitation energies you mentioned are well reproduced (in 
the third line there are oscillator strengths).

Best wishes,

Tatiana

On Thu, 10 Mar 2016, behnam nikoobakht wrote:

> Dear Tatiana
>
> I am calcuating the excitation energies for Acetone molecule using CCSD-eom method.The results of this calculation are in the output file (see attachment). What is strange for me is that there are huge
> differences among the calcuated excitation energies (see output)  and the experimental ones.The experimental values for the five lowest states are 4.43, 6.36, 7.36, 7.41 and 7.49.
> I tried the larger basis set and observed the same issue. In the case of CC2 method, the same problemexsit. 
> It seems that I am doing wrong in this calcuation, but I do not see any problem in my input file.Please let me know if you have some ideas for this issue.
> Thank you very much for your help in advance,Behnam

Dr. Tatiana Korona http://tiger.chem.uw.edu.pl/staff/tania/index.html
Quantum Chemistry Laboratory, University of Warsaw, Pasteura 1, PL-02-093 Warsaw, POLAND