Re: CCL:error in Gaussian98



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:   Victor $#at#$ averell.umh.ac.be
 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: help $#at#$ gaussian.com
 ++++++++++++++++++++++++++
 On Wed, 26 Feb 2003, Igor Avilov wrote:
 > 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.
 >
 >
 >
 >
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  ___________________________________________________________________
       Dr Victor GESKIN         e-mail:   Victor $#at#$ averell.umh.ac.be
       Service de Chimie                   http://morris.umh.ac.be
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  Universite de Mons-Hainaut     phone:     +32-(0)65.37.38.67
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