From chemistry-request&$at$&ccl.net Wed Nov 19 11:04:22 2003 Received: from mail.uvigo.es (mail.uvigo.es [193.146.32.91]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id hAJG3nRW003023 for ; Wed, 19 Nov 2003 11:03:50 -0500 Received: from mail.uvigo.es (localhost [127.0.0.1]) by mail.uvigo.es (8.12.9/8.12.1) with ESMTP id hAJG3nhJ030537 for ; Wed, 19 Nov 2003 17:03:49 +0100 Received: from correo.uvigo.es (correo.uvigo.es [193.146.32.68]) by mail.uvigo.es (8.12.9/8.12.1) with ESMTP id hAJG3nYL030532 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NOT) for ; Wed, 19 Nov 2003 17:03:49 +0100 Received: from correo (correo [193.146.32.68]) by correo.uvigo.es (8.12.9/8.12.5) with ESMTP id hAJG3mpG031830; Wed, 19 Nov 2003 17:03:48 +0100 Date: Wed, 19 Nov 2003 17:03:48 +0100 (CET) From: Carlos Silva Lopez X-X-Sender: To: Jesus Rodriguez-Otero cc: Subject: Re: CCL:qcsid(t) size consistent? In-Reply-To: <5.2.0.9.0.20031119131217.00a2b690|at|pop.usc.es> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 X-Spam-Status: No, hits=-0.5 required=7.0 tests=IN_REP_TO,USER_AGENT_PINE version=2.55 X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from QUOTED-PRINTABLE to 8bit by server.ccl.net id hAJG4MRW003038 Actually size consistency is the only improventent of quadratic methods over classic configuration interaction methods. This is achieved including some higher order excitation terms (quadratic in the expansion coefficients). You might think of it as a simplification of the e^-T expansion which retains size consistency in a coupled cluster calculation. Saludos desde Vigo! _-_-_-_-_-_-_-_-_-_-_-_- Carlos Silva Lspez Dept. Quimica Organica Universidade de Vigo Phone:0034 986812226 -_-_-_-_-_-_-_-_-_-_-_-_