From chemistry-request@ccl.net Tue Apr 27 02:12:36 2004 Received: from rojo2.usc.es (rojo2.usc.es [193.144.75.10]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id i3R7CYKC024747 for ; Tue, 27 Apr 2004 02:12:35 -0500 Received: from localhost (rojo2 [127.0.0.1]) by rojo2.usc.es (Postfix) with ESMTP id 16E2EF715 for ; Tue, 27 Apr 2004 09:13:50 +0200 (CEST) Received: from usuario-hmapt6w.usc.es (qfcronos.usc.es [193.144.74.154]) by rojo2.usc.es (Postfix) with ESMTP id CCD17F70B for ; Tue, 27 Apr 2004 09:13:49 +0200 (CEST) Message-Id: <6.0.1.1.1.20031127091300.01c22e80:at:pop.usc.es> X-Sender: qftjesus:at:pop.usc.es X-Mailer: QUALCOMM Windows Eudora Version 6.0.1.1 Date: Thu, 27 Nov 2003 09:13:51 +0100 To: chemistry:at:ccl.net From: Jesus Rodriguez-Otero Subject: CCL: Pd-ethylene cluster with G98 Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; format=flowed X-Virus-Scanned: by usc.es X-Spam-Status: No, hits=1.2 required=7.5 tests=DATE_IN_PAST_96_XX autolearn=no version=2.61 X-Spam-Checker-Version: SpamAssassin 2.61 (1.212.2.1-2003-12-09-exp) on servernd.ccl.net Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by server.ccl.net id i3R7CaKC024751 Hi netters, I am comparing the performance of HF, DFT/B3LYP anda MP2 with Gaussian98 in a simple calculation of a cluster formed by two Pd atoms and ethylene. To my surprise, b3lyp is much slower than HF or MP2; cpu times are hf: 3 min. 21 s. b3lyp: 1 h. 5 min. mp2: 8 min. 28 s. P-IV running LINUX this is my input file: ------------------------------------------------------------------------------------ %chk=pd2etepa.chk # hf/lanl2mb opt(z-matrix,maxcyc=60) scf(qc,maxcyc=500) Title Card Required 0 1 Pd Pd 1 2.750872 C 1 B1 2 A1 C 3 B2 1 A2 2 D1 H 4 B3 3 A3 1 D2 H 3 B4 4 A4 5 D3 H 4 B5 3 A5 6 D4 H 3 B6 4 A6 7 D5 B1 2.408742 B2 1.354929 B3 1.070182 B4 1.070143 B5 1.070035 B6 1.069670 A1 76.672064 A2 107.368541 A3 120.230124 A4 119.863439 A5 119.916731 A6 120.275618 D1 1.099106 D2 90.171155 D3 0.053786 D4 -179.938316 D5 0.015838 ------------------------------------------------------------------------------------------- Is this normal? Can dft performance be improved? \|/ ( @ @ ) -------oOo-(_)-oOo------------------------------------------------------ Jeszs Rodrmguez-Otero Departamento de Qummica Fmsica, Facultade de Qummica Universidade de Santiago 15782 Santiago de Compostela, (Spain) Phone: (+34)-981563100 ext 14436, Fax: (+34)-981595012 qftjesus:at:usc.es http://web.usc.es/~qftjesus/index.html