CCL:G: localisation of transition states with gaussian
- From: Joaquin Barroso Flores <joaco_barroso(-)yahoo.com>
- Subject: CCL:G: localisation of transition states with
gaussian
- Date: Sun, 29 Jan 2006 19:05:19 -0600 (CST)
Hello,
Have you consider using the ONIOM
approach? you could set a different level of theory for the aromatic moiety,
since based on my own experience DFT methods exhibit convergence problems when
aromatic substituents are present from time to time. I hope this may help
you
good luck
"b wafaa
wafaab2(_)yahoo.fr" <owner-chemistry^ccl.net> escribió:
Sent to CCL by: b wafaa
[wafaab2(_)yahoo.fr]
--0-2071525535-1138445180=:27426
Content-Type:
text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit
Dear
CCLers,
I am studing cycloaddition (Diels-alder, 1,3 dipolar) reactions using
theoretical approaches and I find great difficulties to locate transition states
when bulk substituents (phenyl groups) are present in the reagents.
I use
the options:
B3LYP/6-31G(d) Opt(TS, Noeigentest, Maxcycle=500) freq . However, the
convergence fails after 2 or 3 days of calculation ?.
I need your help for
overcoming this problem if you have ideas about other options or astutenesses
available in gaussian 98W software.
Thank you in advance.
W.
Benchouk
Melle Wafaa BENCHOUK
Laboratoire de Chimie Théorique
et modélisation Moléculaire
Département de Chimie,
Faculté des Sciences,
Université A. Belkaid de Tlemcen, B.P.
119,Tlemcen, 13000, ALGERIA
Tél: + 213 43 28 63 49 poste 229
Fax: +
213 43 28 61 08
e-mail:
benchouk_wafaa*o*yahoo.fr
---------------------------------
Nouveau :
téléphonez moins cher avec Yahoo! Messenger ! Découvez les tarifs
exceptionnels pour appeler la France et l'international.Téléchargez la
version beta.
--0-2071525535-1138445180=:27426
Content-Type: text/html;
charset=iso-8859-1
Content-Transfer-Encoding: 8bit