CCL:G: G03 optimization convergence limits

From: "Igor Avilov" <avilovi(!)averell.umh.ac.be>
Subject: CCL:G: G03 optimization convergence limits
Date: Tue, 26 Jun 2007 10:26:15 +0200

Dear John,

Try using Opt(GDIIS), it helps in cases where the potential energy surface is very flat.

Best wishes,

Igor Avilov.

From: owner-chemistry#ccl.net [mailto:owner-chemistry#ccl.net]
Sent: lundi 25 juin 2007 19:35
To: Igor Avilov
Subject: CCL: G03 optimization convergence limits

Greetings,

Often when there are freely rotating methyl groups one can find that the energy and gradients have converged but there is a large displacement because of the freely rotating or librating methyl group, and a lot of cpu time can go into getting the methyl group to settle down. Does anyone know how to set IOP info to allow a way around this problem [where convergence of the torsion angle of the methyl group is not important]?

Thanks!

John McKelvey