CCL:G: Tweaking Gaussian to remove imaginay frequency

 Sent to CCL by: "Close, David M." [CLOSED%x%mail.etsu.edu]
   John:
 "Tweaks Under Gaussian?" No.  What you have to do is animate the
 frequency output to look at the particular vibration that involves this negative
 frequency.  Then you have to make small changes in the coordinates of this
 motion in attempts to get off the optimization off this local minima in hopes of
 going towards the global minima.  There are free programs on the internet to do
 this, and I can send one to you.  But with a little practice you can guess at
 which numbers to alter.
   Regards, Dave Close.
 -----Original Message-----
 > From: owner-chemistry+closed==etsu.edu]_[ccl.net [mailto:owner-chemistry+closed==etsu.edu]_[ccl.net] On Behalf Of John Simmie
 john.simmie===nuigalway.ie
 Sent: Monday, November 03, 2014 8:46 AM
 To: Close, David M.
 Subject: CCL:G: Tweaking Gaussian to remove imaginay frequency
 Sent to CCL by: "John  Simmie" [john.simmie%%nuigalway.ie] In running
 a B3LYP/6-311G(2d,d,p) geometry/frequency calculation of the all-trans conformer
 of succinic acid
 0,1
 1       -2.350831000      2.938540000      0.000000000
 8       -1.422415000      2.661642000      0.000000000
 8       -2.436452000      0.657377000      0.000000000
 6       -1.422415000      1.308099000      0.000000000
 6       -0.015143000      0.761522000      0.000000000
 1        0.511721000      1.167432000      0.867888000
 1        0.511721000      1.167432000     -0.867888000
 6        0.015143000     -0.761522000      0.000000000
 1       -0.511721000     -1.167432000     -0.867888000
 1       -0.511721000     -1.167432000      0.867888000
 6        1.422415000     -1.308099000      0.000000000
 8        2.436452000     -0.657377000      0.000000000
 8        1.422415000     -2.661642000      0.000000000
 1        2.350831000     -2.938540000      0.000000000
 I end up with a imaginary frequency. Given THAT functional and basis set are
 there any general tweaks under Gaussian-09 that I can make which will eliminate
 it?  Should one loosen or tighten limts or what?  Opt-VTight does not help ...
 john.simmie at NUIGalway.iehttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp-:-//www.ccl.net/chemistry/sub_unsub.shtmlhttp-:-//www.ccl.net/spammers.txt