Subject: TDDFT excited state calculation in G98

From: "Hui-Hsu \(Gavin\) Tsai" <[email-masked]>
Date: Sun, 9 Sep 2001 21:49:00 -0400

Hi CCLers,

      We have a question about excited state calculations by using G98W.
  In the excited state calculation (such as TDDFT), are the coefficients normalized?
Why is the sum of the squared coefficients not equal to 1.0
and sometimes smaller than 0.5?

    Here is the output of TDDFT calculations of water... 

  Excitation energies and oscillator strengths:
 
  Excited State   1:   Singlet-B1     8.0068 eV  154.85 nm  f=0.0142
       3 -> 14        -0.01126
       5 ->  6         0.69120
       5 -> 11         0.01351
 This state for optimization and/or second-order correction.
 Total Energy, E(RPA) =  -76.1254896781    
 Copying the excited state density for this state as the 1-particle RhoCI density.
 
 Excited State   2:   Singlet-A2    10.0437 eV  123.44 nm  f=0.0000
       5 ->  7         0.70034
       5 ->  8        -0.01585
       5 -> 12         0.01756

   The water example shows that the sum of the squared coefficients is about just 0.5.

   Should we normalize the coefficients by ourselves? 
  
  any comment or advice is welcomed.

   Thanks.

  Gavin