Subject: explanation of excited state calculation

From: "Deng, Jun" <jdeng_at_ppg.com>
Date: Wed, 8 Oct 2003 11:56:33 -0400

Dear college:

I am having a hard time to rationalize the vertical excited state calculation.  Here are two examples from TDDFT calculation.  The first example shows the first singlet excited state is at 519 nm with intensity of 0.8344 and it is from HOMO -> LUMO, which makes sense to me.  However, in the 2nd example, the major contribution of first several excited states are not from HOMO->LUMO any more and their intensity are very low, what is causing this?  How to rationalize that the lowest absorption band is not from HOMO->Lumo in example 2?  How to explain their low intensity?

Thank you very much in advance!

Jun Deng

Example 1:
------------------
.....
 Excitation energies and oscillator strengths:
 
 CIS wavefunction symmetry could not be determined.
 Excited State   1:   Singlet-?Sym    2.3877 eV  519.25 nm  f=0.8344
     111 ->112         0.60683
 This state for optimization and/or second-order correction.
 Copying the excited state density for this state as the 1-particle RhoCI density.
 
 CIS wavefunction symmetry could not be determined.
 Excited State   2:   Singlet-?Sym    2.7187 eV  456.04 nm  f=0.0143
     109 ->112         0.66284
     110 ->112         0.15775
 
 CIS wavefunction symmetry could not be determined.
 Excited State   3:   Singlet-?Sym    2.9144 eV  425.41 nm  f=0.1573
     108 ->112         0.10820
     109 ->112        -0.15727
     110 ->112         0.64066

 **********************************************************************

Example 2:
----------------
...

 Excitation energies and oscillator strengths:
 
 CIS wavefunction symmetry could not be determined.
 Excited State   1:   Singlet-?Sym    1.8767 eV  660.63 nm  f=0.0018
     108 ->115        -0.11035
     108 ->116         0.20162
     109 ->111         0.51094
     109 ->112        -0.11881
     109 ->115        -0.31646
     109 ->116        -0.12306
     109 ->117        -0.14693
     110 ->116         0.14532
 This state for optimization and/or second-order correction.
 Copying the excited state density for this state as the 1-particle RhoCI density.
 
 CIS wavefunction symmetry could not be determined.
 Excited State   2:   Singlet-?Sym    1.9109 eV  648.81 nm  f=0.0440
     108 ->111         0.36507
     108 ->112        -0.10467
     108 ->115        -0.27320
     108 ->116        -0.10897
     108 ->117        -0.13976
     109 ->111        -0.11460
     109 ->115         0.13735
     109 ->116        -0.25594
     110 ->111         0.30348
     110 ->115        -0.17043
 
 CIS wavefunction symmetry could not be determined.
 Excited State   3:   Singlet-?Sym    2.3975 eV  517.14 nm  f=0.0985
     105 ->111         0.18235
     105 ->115        -0.22021
     105 ->117        -0.11614
     108 ->116         0.13778
     109 ->114        -0.11851
     109 ->115        -0.12217
     109 ->116         0.43242
     110 ->111         0.28462
 
 CIS wavefunction symmetry could not be determined.
 Excited State   4:   Singlet-?Sym    2.4312 eV  509.97 nm  f=0.0116
     105 ->116         0.17280
     108 ->114         0.11007
     108 ->115         0.13363
     108 ->116        -0.39502
     109 ->111         0.32852
     109 ->115         0.10826
     109 ->116         0.17199
     109 ->117         0.10013
     110 ->111         0.11137
     110 ->116        -0.25594
 
 CIS wavefunction symmetry could not be determined.
 Excited State   5:   Singlet-?Sym    2.5613 eV  484.07 nm  f=0.3805
     105 ->111        -0.12691
     105 ->115         0.17900
     107 ->111         0.16390
     108 ->111        -0.30706
     109 ->116        -0.13230
     110 ->111         0.42057
 
 CIS wavefunction symmetry could not be determined.
 Excited State   6:   Singlet-?Sym    2.6477 eV  468.27 nm  f=0.0142
     105 ->111        -0.22953
     105 ->115         0.22375
     105 ->117         0.11472
     106 ->111        -0.12855
     108 ->111         0.44043
     108 ->115         0.18104
     108 ->117         0.12017
     109 ->115        -0.10034
     110 ->115         0.18972
     110 ->117         0.10481

 **********************************************************************