Author Topic: visualize ricc2 and escf orbitals for excited states  (Read 5124 times)

jbaltrus

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visualize ricc2 and escf orbitals for excited states
« on: June 29, 2011, 04:45:11 am »
I am somewhat confused on which orbitals are used and need to be visualized for excited states calculated via ricc2 and escf (tddft b3lyp)? Are those dscf (ridft) orbitals or localized orbitals or some other orbitals? In which file are they stored so I can visualize them with Tmolex?

In ricc2 I am getting these plotted, are these used for excited state construction?
    +--------------------------------------------------------------------+
     | CC2 unrelaxed natural orbital occupation numbers                   |
     +--------------------------------------------------------------------+
     | natural orb.  |  occupation numbers                                |
     +---------------+----------------------------------------------------+
     | a             |                                                    |
     |     1 -     5 |     2.0000    2.0000    2.0000    2.0000    2.0000 |
     |     6 -    10 |     2.0000    2.0000    2.0000    2.0000    2.0000 |
     |    11 -    15 |     2.0000    2.0000    2.0000    2.0000    2.0000 |

christof.haettig

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Re: visualize ricc2 and escf orbitals for excited states
« Reply #1 on: August 12, 2011, 09:43:25 am »
TDDFT and coupled-cluster response methods (CC2) both expand the excited state wavefunctions in the same orbitals as the ground state.

The natural orbitals are not very useful for visualizing excited state wavefunctions.

What you can do (with the current version of TM) are two things:
  - you can look at the coefficients  of the most important orbital transitions (i.e. singly excited determinants) which contribute to a given
    excited state and visualize the (ground state) orbitals involved in these transitions
 - you can plot the difference between the ground and excited state densities (see the manual for a description how this can be done).
   This difference density tells you, from where to where charge is shifted upon the excitation. You easily recognize from this
    difference density whether i.e. is a local or a charge transfer or a Rydberg excitation and for planar molecules you distinguish   
   between  n pi* and pi pi* transitions.

Christof