[molpro-user] regarding characterization of rydberg state

[Tatiana Korona]

Dear Tanmoy,

In general (not only fo EOM-CCSD) you need to estimate a spatial extent of the 
excited state and to compare if it is considerably larger than the same quantity 
for the ground state. For this purpose 1-RDM (reduced density matrices) for both 
states can be used. An example how to calculate them for CCSD (ground state) and 
EOM-CCSD is given e.g. in $molpro/examples/hf_eom_prop.com, where instead of 
expec,qm you should put expec,qmrr. In the output you should find and compare 
(numbers are for hf_eom_prop)

!CCSD expec         <1.1|QMRR|1.1>   -11.517973774572

and e.g.

!EOM-CCSD expec. ex <2.2|QMRR|2.2>   -37.714757125305

so for the state 2.2 RR=XX+YY+ZZ is ca. 3.3 times larger than for the state 1.1 
(ground state). You should find in the literature what ratios should be expected 
for Rydberg states.

Note that the calculation of the 1st order properties in CCSD and EOM-CCSD is 
about 2 times more expensive than the calculation of energies only.

Best wishes,

Tatiana


On Tue, 2 Mar 2010, TANMOY MONDAL wrote:

> 
> 
> Dear molpro-users,
> 
> Can anybody please tell me to characterized any excited state as rydberg state in EOM-CCSD output in molpro programm
> package.
> 
> With regards
> 
> Tanmoy Mondal
> University of Hyderabad
> Hyderabad - 46. INDIA.
> 
>

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


`The man who makes no mistakes does not usually make anything.'
                                        Edward John Phelps (1822-1900)