# CCL:G: Why "Eigenvalues" in the Gaussian output file are so
large?

*From*: Gustavo Seabra <gustavo.seabra*_*gmail.com>
*Subject*: CCL:G: Why "Eigenvalues" in the Gaussian output
file are so large?
*Date*: Tue, 7 Apr 2009 13:53:36 -0400

Sent to CCL by: Gustavo Seabra [gustavo.seabra~!~gmail.com]
On Thu, Apr 2, 2009 at 6:26 PM, Roman D Gorbunov
rgorbuno(-)aecom.yu.edu <owner-chemistry]-[ccl.net> wrote:
>
> Sent to CCL by: "Roman D Gorbunov" [rgorbuno ~~ aecom.yu.edu]
> Dear CCL Subscribers,
>
> In my Gaussian output file I found the following lines:
>
> Eigenvalues --- 0.61543 0.75911
0.790561000.000001000.00000
> Eigenvalues --- 1000.000001000.000001000.000001000.000001000.00000
> Eigenvalues --- 1000.000001000.000001000.000001000.000001000.00000
>
> It looks suspicious. However I still have the "Normal
termination".
>
> Does anybody know what these "Eigenvalues" means and why they are
equal to "1000.00000"?
>
> Could these lines be an indication that something wrong with my
calculations or I should not wary about that?
>
> Thank you in advance,
> Roman
Those values do look *very* suspicious. Not only because of the
magnitude (which is suspicious by itself), but the printing format
itself seems different from the standard format in Gaussian. Did you
change anything in your Gaussian installation? Maybe someone touched
the code and recompiled it? I seem to recall (it's been a long time)
that Gaussian used to have a test set to test the installation. Do all
the test pass?
As far as your calculation goes, those seem to be virtual orbitals and
to be lying very far above the system energies. But if this is messed
up, everything else may be as well... What kind of calculations are
you trying? Also, what version of Gaussian are you using? would you be
comfortable posting the input file you used so others can try to
reproduce what you are seeing?
Gustavo.