From owner-chemistry@ccl.net Mon Sep 27 17:37:00 2010 From: "Jim Kress ccl_nospam=kressworks.com" To: CCL Subject: CCL: problem with fixing a bond Message-Id: <-42844-100927155448-6707-7PsYfBPBEsHUvUKgHqKZRw*server.ccl.net> X-Original-From: "Jim Kress" Content-Language: en-us Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01CB5E5C.4804FE00" Date: Mon, 27 Sep 2010 15:54:31 -0400 MIME-Version: 1.0 Sent to CCL by: "Jim Kress" [ccl_nospam{}kressworks.com] This is a multi-part message in MIME format. ------=_NextPart_000_0006_01CB5E5C.4804FE00 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit What software are you using and what do your input and output files look like? Jim > From: owner-chemistry+ccl_nospam==kressworks.com[-]ccl.net [mailto:owner-chemistry+ccl_nospam==kressworks.com[-]ccl.net] On Behalf Of SUBHADEEP SAHA saha.subhadeep*gmail.com Sent: Monday, September 27, 2010 11:04 AM To: Kress, Jim Subject: CCL: problem with fixing a bond Dear all, I am trying to optimize(b3lyp/6-31g) a structure freezing almost 20 atoms and 30 bonds.Now the problem is crashing after a running number of steps giving the following error Iteration100 RMS(Cart)= 0.00000470 RMS(Int)= 0.01035587 New curvilinear step not converged. Error imposing constraints I checked the final configuration and got that the some of the groups(which are from the frozen bonds only,suppose I have frozen the C-H bonds of CH3 groups) moves away from initial configuration after feeling some favorable interaction elsewhere. I have checked CCL archives"http://server.ccl.net/cgi-bin/ccl/message-new?2003+05+23+007".But did not get any satisfactory solution to optimizing the structure keeping the constrains(Whatever I have provided) same. Can anyone please suggest a solution? Thanks in advance... Regards, Subhadeep Saha C/O Dr.Rahul Banerjee Materials and Physical Chemistry Division National Chemical Laboratory Dr. Homi Bhabha Road Pune:411008 Maharasthra India Ph:+91-20-2590-2387 +91-20-2590-2535 +91-20-2590-2598 ------=_NextPart_000_0006_01CB5E5C.4804FE00 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

What software are you using and what do your input and = output files look like?

Jim

From:= owner-chemistry+ccl_nospam=3D=3Dkressworks.com[-]ccl.net [mailto:owner-chemistry+ccl_nospam=3D=3Dkressworks.com[-]ccl.net] On = Behalf Of SUBHADEEP SAHA saha.subhadeep*gmail.com
Sent: Monday, September 27, 2010 11:04 AM
To: Kress, Jim
Subject: CCL: problem with fixing a bond

Dear all,

I am trying to optimize(b3lyp/6-31g) a structure freezing almost 20 = atoms and 30 bonds.Now the problem is crashing after a running number of steps giving the following error

Iteration100 RMS(Cart)=3D 0.00000470 RMS(Int)=3D = 0.01035587
New curvilinear step not converged.
Error imposing constraints

I checked the final configuration and got that the some of the = groups(which are > from the frozen bonds only,suppose I have frozen the C-H bonds of CH3 = groups) moves away from initial configuration after feeling some favorable = interaction elsewhere.

I have checked CCL archives"htt= p://server.ccl.net/cgi-bin/ccl/message-new?2003+05+23+007".But did not get any satisfactory solution to optimizing the structure = keeping the constrains(Whatever I have provided) same.

Can anyone please suggest a solution?

Thanks in advance...

Regards,
Subhadeep Saha
C/O Dr.Rahul Banerjee
Materials and Physical Chemistry Division
National Chemical Laboratory
Dr. Homi Bhabha Road
Pune:411008
Maharasthra
India
Ph:+91-20-2590-2387
+91-20-2590-2535
+91-20-2590-2598

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