<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-04-17T14:18:55Z</responseDate><request verb="GetRecord" identifier="oai:www.recercat.cat:2445/199749" metadataPrefix="qdc">https://recercat.cat/oai/request</request><GetRecord><record><header><identifier>oai:recercat.cat:2445/199749</identifier><datestamp>2025-12-04T20:48:29Z</datestamp><setSpec>com_2072_1057</setSpec><setSpec>col_2072_478822</setSpec><setSpec>col_2072_478917</setSpec></header><metadata><qdc:qualifieddc xmlns:qdc="http://dspace.org/qualifieddc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://purl.org/dc/elements/1.1/ http://dublincore.org/schemas/xmls/qdc/2006/01/06/dc.xsd http://purl.org/dc/terms/ http://dublincore.org/schemas/xmls/qdc/2006/01/06/dcterms.xsd http://dspace.org/qualifieddc/ http://www.ukoln.ac.uk/metadata/dcmi/xmlschema/qualifieddc.xsd">
   <dc:title>Variational localized-site cluster expansions. II. Trees and near trees</dc:title>
   <dc:creator>Klein, D.J.</dc:creator>
   <dc:creator>García Bach, Ma. de los Ángeles</dc:creator>
   <dc:subject>Termodinàmica estadística</dc:subject>
   <dc:subject>Teoria de grafs</dc:subject>
   <dc:subject>Arbres</dc:subject>
   <dc:subject>Statistical thermodynamics</dc:subject>
   <dc:subject>Graph theory</dc:subject>
   <dc:subject>Trees</dc:subject>
   <dcterms:abstract>Cluster expanded wavefunctions involving localized‐site states and only pair excitations between nearest neighbor sites are considered. In the case that the bonds connecting these nearest neighbor sites form a tree graph (without rings), exact matrix element formulas are obtained in terms of the inverse of a modified type of topological matrix associated with this tree graph. The treatment of some near‐tree cases, without any touching rings, is also discussed.</dcterms:abstract>
   <dcterms:issued>2023-06-23T16:45:59Z</dcterms:issued>
   <dcterms:issued>2023-06-23T16:45:59Z</dcterms:issued>
   <dcterms:issued>1976</dcterms:issued>
   <dcterms:issued>2023-06-23T16:45:59Z</dcterms:issued>
   <dc:type>info:eu-repo/semantics/article</dc:type>
   <dc:type>info:eu-repo/semantics/publishedVersion</dc:type>
   <dc:relation>Reproducció del document publicat a: https://doi.org/10.1063/1.432144</dc:relation>
   <dc:relation>Journal of Chemical Physics, 1976, vol. 64, p. 4873-4877</dc:relation>
   <dc:relation>https://doi.org/10.1063/1.432144</dc:relation>
   <dc:rights>(c) American Institute of Physics (AIP), 1976</dc:rights>
   <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
   <dc:publisher>American Institute of Physics (AIP)</dc:publisher>
   <dc:source>Articles publicats en revistes (Física de la Matèria Condensada)</dc:source>
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