# [DFTB-Plus-User] Excited State calculation: Multiple StateOfInterest and format of TRA.DAT

Dirk Ziemann dirk.ziemann at physik.hu-berlin.de
Wed Jun 28 16:49:37 CEST 2017

```Dear all,

I have two questions concerning the excited state calculation.

I am interested in the Mulliken charges of many different excited
states. If I specify a single state of interest at StateOfInterest
everything works fine, but there is an error for multiple numbers. Is it
possible to get the Mulliken charges for many different states at
once?            (I need >1000 states)

In my TRA.DAT files I see the following lines (see below). Why does a
transition appears multiple times?

As far as I have checked it, this happens only to the first transition.I
have a feeling that it is related to the value of OscillatorWindow. If I
choose a high value this does not happen. The smaller the value the
higher the number of "multiple first transitions".

Thank you for your help and best wishes   Dirk

everything the same in dftb_in.hsd except the  ExcitedState-part

example 1:

Energy      1          3.625 eV   S

Transition         Weight       KS [eV]
=============================================
13723   -> 13908     0.7361       4.616
13723   -> 13908     0.5047       4.616
13723   -> 13908     0.3897       4.616
13723   -> 13908     0.2272       4.616
1011   -> 20029     0.0000      39.368
1011   -> 20028     0.0000      39.368

dftb_in.hsd

ExcitedState {
Casida {
NrOfExcitations = 100
StateOfInterest = 0
Symmetry = singlet
OscillatorWindow = 1E-1
WriteStatusArnoldi = Yes
WriteTransitions = Yes
}
}

//==============================================//

example 2

Energy      1          3.754 eV   S

Transition         Weight       KS [eV]
=============================================
13749   -> 13754     0.8301       3.754
13749   -> 13754     0.4022       3.754
13749   -> 13754     0.3398       3.754
13749   -> 13754     0.1559       3.754
13749   -> 13754     0.0687       3.754
13749   -> 13754     0.0550       3.754
13749   -> 13754     0.0417       3.754
215   -> 20033     0.0000      39.768
215   -> 20035     0.0000      39.768

dftb_in.hsd

ExcitedState {
Casida {
NrOfExcitations = 30
StateOfInterest = 0
Symmetry = singlet
OscillatorWindow = 1E-2
WriteStatusArnoldi = Yes
WriteTransitions = Yes
}
}

--
Dirk Ziemann
Humboldt Universität zu Berlin, Institut für Physik

```