From owner-nwchem-users@emsl.pnl.gov Fri Jul 27 11:07:03 2007 Received: from odyssey.emsl.pnl.gov (localhost [127.0.0.1]) by odyssey.emsl.pnl.gov (8.13.8/8.13.8) with ESMTP id l6RI72Vm007084 for ; Fri, 27 Jul 2007 11:07:03 -0700 (PDT) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.13.8/8.13.8/Submit) id l6RI72Re007083 for nwchem-users-outgoing-0915; Fri, 27 Jul 2007 11:07:02 -0700 (PDT) X-Authentication-Warning: odyssey.emsl.pnl.gov: majordom set sender to owner-nwchem-users@emsl.pnl.gov using -f X-Ironport-SG: OK_Domains X-Ironport-SBRS: 4.7 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAAF7RqUarQAqYk2dsb2JhbACCZY0EAQECBwQGBwgYn0o X-IronPort-AV: E=Sophos;i="4.16,589,1175497200"; d="scan'208,217";a="27015486" Message-Id: <200707271806.l6RI6xAh006872@smtp-roam.Stanford.EDU> From: "zyzhang" To: Subject: [NWCHEM] TS calculation with NWChem Date: Fri, 27 Jul 2007 11:07:00 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002E_01C7D03E.416E5CD0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 Thread-Index: AcfQeO1+68STi2tsTWGdBlV6QegMOg== Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk This is a multi-part message in MIME format. ------=_NextPart_000_002E_01C7D03E.416E5CD0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi All, We are doing a transition state search for H2 dissociation and having trouble converging to the TS. The program followed a decent negative mode (eigen val ca. -0.04) for many steps but still slipped away from the TS. Does any body have some suggestions to improve the convergence? Should I try to do a freq calculation first and continue to search the TS? Are there any other simpler ways to try first before taking this kind of approach? (like trust radii?) It is a relatively large calculation so I'd like to have some advices from the experts before I run it again. Thanks a lot and regards, Zhiyong ------=_NextPart_000_002E_01C7D03E.416E5CD0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Hi All,

 

We are doing a transition state search for H2 = dissociation and having trouble converging to the TS. The program followed a decent = negative mode (eigen val ca. -0.04) for many steps but still slipped away from = the TS. Does any body have some suggestions to improve the convergence? Should I try = to do a freq calculation first and continue to search the TS? Are there any = other simpler ways to try first before taking this kind of approach? (like = trust radii?) It is a relatively large calculation so I’d like to have = some advices from the experts before I run it again. =

 

Thanks a lot and regards, =

Zhiyong

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