From chemistry-request@ccl.net Tue Apr 13 21:22:04 2004 Received: from hotmail.com (sea2-dav69.sea2.hotmail.com [207.68.164.204]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id i3E2M2uR014367 for ; Tue, 13 Apr 2004 21:22:03 -0500 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Tue, 13 Apr 2004 19:22:24 -0700 Received: from 150.29.165.186 by sea2-dav69.sea2.hotmail.com with DAV; Wed, 14 Apr 2004 02:22:23 +0000 X-Originating-IP: [150.29.165.186] X-Originating-Email: [amelnahas=at=hotmail.com] X-Sender: amelnahas=at=hotmail.com Reply-To: "Ahmed El-Nahas" From: "Ahmed El-Nahas" To: Subject: IRC&ISPE Date: Wed, 14 Apr 2004 12:25:37 -0700 Organization: Science MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00D2_01C4221B.976F6D60" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Message-ID: X-OriginalArrivalTime: 14 Apr 2004 02:22:24.0140 (UTC) FILETIME=[529C4CC0:01C421C7] X-Spam-Status: No, hits=2.0 required=7.5 tests=DATE_IN_FUTURE_12_24, HTML_MESSAGE autolearn=no version=2.61 X-Spam-Checker-Version: SpamAssassin 2.61 (1.212.2.1-2003-12-09-exp) on servernd.ccl.net This is a multi-part message in MIME format. ------=_NextPart_000_00D2_01C4221B.976F6D60 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear CCLs, I wonder if someone could help me regarding running IRC calculations. I = want to use a gradient stepsize of 0.05 (amu)1/2 bohr, shall I use = StepSize=3D5 in this case?. And how I can get many points, say from = s=3D-2 to s=3D2.5?. Also when I used Maxpoints=3D20, for example with = this stepSize=3D10 I got only 8 points. But when I use Maxpoints=3D50 = without specifying stepsize, I got 36 points. Once more, how I can = calculate frequency at each two or three points?. The Freq keyword = doesn't work, or doesn't recognized by this version of Gaussian98. By the way, regarding Truhlar method (JPCA, 1999, 103,1140) for = correcting energy profiles, that is called ISPE method (interpolated = single-point energies). In that method the authors used high energy = calculations for the stationary points and some selected non-stationary = points along the MEM. Moreover, shall I select these non-stationary = points near te TS or the lowest points along the path and carry out SP = energy calcuations for them at higher levels? Thanks in advance Regards Ahmed ------=_NextPart_000_00D2_01C4221B.976F6D60 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear CCLs,

I wonder if someone could help me = regarding=20 running IRC calculations. I want to use a gradient stepsize of 0.05 = (amu)1/2 bohr, shall I use StepSize=3D5 in this case?. And how I can get = many=20 points, say from s=3D-2 to s=3D2.5?. Also when I used Maxpoints=3D20, = for example with=20 this stepSize=3D10 I got only 8 points. But when I use = Maxpoints=3D50 without=20 specifying stepsize, I got 36 points. Once more, how I can calculate = frequency=20 at each two or three points?. The Freq keyword doesn't work, or doesn't=20 recognized by this version of Gaussian98.

By the way, regarding Truhlar method (JPCA, 1999, 103,1140) for=20 correcting energy profiles, that is called ISPE method = (interpolated=20 single-point energies). In that method the authors used high energy = calculations=20 for the stationary points and some selected non-stationary points along = the MEM.=20 Moreover, shall I select these non-stationary points near te TS = or the=20 lowest points along the path and carry out SP energy calcuations for = them at=20 higher levels?

Thanks in advance

Regards

Ahmed

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