Subject: CCL: TD-DFT on open shell systems

From: "Jens Spanget-Larsen" <[email-masked]>
Date: Fri, 30 Nov 2001 12:02:14 +0100

Yi Gao:

> When I use Guassian98 to deal with open-shell systems, I found that
> the TDDFT could also do work. But the Guassian's reference say TDDFT
> could only deal with close-shell systems. I want to know whether the
> results obtained reliable or not?

Gaussian98 will perform TD-DFT calculations on open shell systems. 
For example, a recent TD-UB3LYP/cc-pVTZ calculation on the phenoxyl 
radical yielded excellent results for low energy electronic 
transitions [a]:

 TD-UB3LYP/cc-pVTZ    Obs., Ar matrix
        cm-1(f)        cm-1(eps,+/-50%)

2-B2    8300(0)        8900(-)
2-A2   19200(0.005)   16000(150)
2-B1   28900(0.029)   25200(3600)
2-A2   36300(0.042)   33900(9600)
2-B1   44000(0.150)   41800(13000)

Unfortunately, the Gaussian output does not contain any precise 
information on the spin properties of the computed excited states. 
Does anybody know how to extract such information, say, the 
expectation value of S^2 ?

Yours, Jens >--<

[a] G. Radziszewski, M. Gil, A. Gorski, J. Spanget-Larsen, J. Waluk, 
B.J. Mroz: "Electronic states of the phenoxyl radical", J. Chem. 
Phys. 115, December 2001.  

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