Subject: error in Gaussian98

From: Igor Avilov <[email-masked]>
Date: Wed, 26 Feb 2003 15:43:43 +0200

Dear CCl users!

 Could you help me with the following problem, please?

 I'm trying to compute the vibrational spectrum of the large molecule
 in the triplet state at UB3LYP/6-31G(d) level. Basis include 638
 basis functions. After several days computation ends up in the
 following way (without indication of the error type):

 Annihilation of the first spin contaminant:
 S**2 before annihilation     2.0607,   after     2.0020
 Range of M.O.s used for correlation:     1   638
 NBasis=   638 NAE=   134 NBE=   132 NFC=     0 NFV=     0
 NROrb=    638 NOA=   134 NOB=   132 NVA=   504 NVB=   506

 **** Warning!!: The smallest alpha delta epsilon is  0.51253642D-01

 **** Warning!!: The smallest beta delta epsilon is  0.57596594D-01

 G2DrvN: will do   36 atoms at a time, making    2 passes doing MaxLOS=2.
 FoFDir used for L=0 through L=2.
          Differentiating once with respect to electric field.
                with respect to dipole field.
          Differentiating once with respect to nuclear coordinates.
 Integrals replicated using symmetry in FoFDir.
 MinBra= 0 MaxBra= 2 Meth= 1.
 IRaf=       0 NMat= 110 IRICut=     110 DoRegI=T DoRafI=T ISym2E= 2 JSym2E=2.
 Raff turned off since only 44.01% of shell-pairs survive.
          There are 219 degrees of freedom in the 1st order CPHF.
 writwa

 Best regards,
 Igor Avilov.

---

From: Victor Geskin <[email-masked]>
Date: Wed, 26 Feb 2003 15:56:42 +0100 (NFT)

I am forwarding the reply to a similar question, concerning the warning, I
recently obtained from the Gaussian support. (Though my calculation
terminated normally.) So, the problem might be in diffuse functions, see
below.

   Victor GESKIN         e-mail:   [email-masked]

TD-DFT Warning in Gaussian

   This message can be considered a warning. In other words, the results
are not necessary erroneous. If the delta-epsilon were too small, the
error message would be "Fatal Problem: The smallest beta delta
epsilon...". The usual cause of this warning is too much linear
dependence in the basis set. Basis set linear dependency is often
associated with the presence of very diffuse functions in the basis
set, so one must balance the desire to have diffuse functions to
describe the excited states with the possible numerical problems
associated with too many diffuse functions, or functions that are too
diffuse.

Regards,
Jim Hess

++++++++++++++++++++++++++
James Hess, Ph.D.
Customer Support Scientist
Gaussian, Inc.
e-mail: [email-masked]
++++++++++++++++++++++++++

On Wed, 26 Feb 2003, Igor Avilov wrote:

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