{"?xml":{"@version":"1.0"},"edm:RDF":{"@xmlns:dc":"http://purl.org/dc/elements/1.1/","@xmlns:edm":"http://www.europeana.eu/schemas/edm/","@xmlns:wgs84_pos":"http://www.w3.org/2003/01/geo/wgs84_pos","@xmlns:foaf":"http://xmlns.com/foaf/0.1/","@xmlns:rdaGr2":"http://rdvocab.info/ElementsGr2","@xmlns:oai":"http://www.openarchives.org/OAI/2.0/","@xmlns:owl":"http://www.w3.org/2002/07/owl#","@xmlns:rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","@xmlns:ore":"http://www.openarchives.org/ore/terms/","@xmlns:skos":"http://www.w3.org/2004/02/skos/core#","@xmlns:dcterms":"http://purl.org/dc/terms/","edm:WebResource":[{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-3Y2E560Y/66b95bd0-da09-4082-9bd1-88056cc84e0d/HTML","dcterms:extent":"38 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-3Y2E560Y/e6ad4c2d-2121-445a-bd42-ad613c9678c7/PDF","dcterms:extent":"459 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-3Y2E560Y/65ecda0e-5282-41fa-9f5a-0118759e3161/TEXT","dcterms:extent":"36 KB"}],"edm:TimeSpan":{"@rdf:about":"1998-2025","edm:begin":{"@xml:lang":"en","#text":"1998"},"edm:end":{"@xml:lang":"en","#text":"2025"}},"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:doc-3Y2E560Y","dcterms:isPartOf":[{"@rdf:resource":"https://www.dlib.si/details/URN:NBN:SI:spr-KC6O72BG"},{"@xml:lang":"sl","#text":"Acta chimica slovenica"}],"dcterms:issued":"2006","dc:creator":["Dolenc, Jožica","Koller, Jože"],"dc:format":[{"@xml:lang":"sl","#text":"številka:3"},{"@xml:lang":"sl","#text":"letnik:53"},{"@xml:lang":"sl","#text":"9 strani"},{"@xml:lang":"sl","#text":"str. 229-237"}],"dc:identifier":["ISSN:1318-0207","COBISSID:27962117","URN:URN:NBN:SI:doc-3Y2E560Y"],"dc:language":"en","dc:publisher":{"@xml:lang":"sl","#text":"Slovensko kemijsko društvo"},"dc:subject":[{"@xml:lang":"sl","#text":"abinitio računalniške metode"},{"@xml:lang":"sl","#text":"atomi"},{"@xml:lang":"sl","#text":"fizikalna kemija"},{"@xml:lang":"sl","#text":"interekcije"},{"@xml:lang":"sl","#text":"kvantna mehanika"},{"@xml:lang":"sl","#text":"računalniški programi"},{"@xml:lang":"sl","#text":"semiempirične metode"},{"@xml:lang":"sl","#text":"voda"},{"@xml:lang":"sl","#text":"vodikova vez"},{"@xml:lang":"sl","#text":"vodikovi vezani sistemi"}],"dcterms:temporal":{"@rdf:resource":"1998-2025"},"dc:title":{"@xml:lang":"sl","#text":"An improved semiempirical MO PM3 method for hydrogen-bonded systems|"},"dc:description":[{"@xml:lang":"sl","#text":"Semiempirical methods are known to show artifacts in predicting the interaction energies and structures of hydrogen-bonded systems. The origin of the artifacts is the correction function of the core-core interaction term, which was introduced to adjust the repulsion between the nuclei. Recently a new PM3 core-core correction function based on the atom-atom parameters has been proposed and the parameters for O-O, O-H, and H-H interactions have been reported. In this work the new core-core correction function has been implemented in the semiempirical molecular orbital package MOPAC97. The test calculations have been performed on the following simple systems; a protonated water dimer, a cyclic water trimer, a cyclic water tetramer, four conformers of a water dimer, a water monomer, an oxonium ion, hydrogen peroxide, and hydrogen trioxide. The results were compared to the values obtained with the standard PM3 method, ab initio methods, and to experimental data, where available. In all of the examples, except for the case of hydrogenperoxide, the modified semiempirical PM3 method provides a significant improvement of the description of the geometries and interaction energies of the test systems, indicating that the reparametrization of the core-core interaction term may play an important role in the future development of semiempirical methods"},{"@xml:lang":"sl","#text":"Znano je, da semiempirične metode slabo napovedujejo energije vodikovo vezanih sistemov in njihovo geometrijo. Vzrok temu je korekcijska funkcija pri členu, ki predstavlja interakcijo med sredicama atomov. Funkcija naj bi modelirala odboj med pari jeder atomov. Nedavno so v semiempirični model PM3 vpeljali novo korekcijsko funkcijo, ki je osnovana na parametrih po parih atomov. Objavili so tudi parametre za interakcijo parov O-O, O-H in H-H. V naši študiji smo omenjeno funkcijo vgradili v programski paket za semiempirične molekulsko orbitalne račune MOPAC97. Testne račune smo naredili na naslednjih enostavnih sistemih; molekuli vode, protoniranem dimeru vode, cikličnem trimeru in tetrameru vode, štirih različnih dimerih vode, oksonijevem ionu, vodikovem peroksidu in vodikovem trioksidu. Rezultate računov smo primerjali s tistimi, ki smo jih dobili s standardno PM3 metodo, ab initio metodami ter z eksperimentalnimi podatki, če obstajajo. V vseh primerih z izjemo vodikovega peroksida se je modificirana PM3 metoda pokazala kot bistveno boljša tako za opis geometrij kot tudi za velikosti interakcijskih energij testnih sistemov. Naše raziskave torej nakazujejo, da bo reparametrizacija člena za interakcijo sredic atomov igrala pomembno vlogo pri nadaljnjem razvoju semiempiričnih metod"}],"edm:type":"TEXT","dc:type":[{"@xml:lang":"sl","#text":"znanstveno časopisje"},{"@xml:lang":"en","#text":"journals"},{"@rdf:resource":"http://www.wikidata.org/entity/Q361785"}]},"ore:Aggregation":{"@rdf:about":"http://www.dlib.si/?URN=URN:NBN:SI:doc-3Y2E560Y","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:doc-3Y2E560Y"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:doc-3Y2E560Y/e6ad4c2d-2121-445a-bd42-ad613c9678c7/PDF"},"edm:rights":{"@rdf:resource":"http://creativecommons.org/licenses/by/4.0/"},"edm:provider":"Slovenian National E-content Aggregator","edm:intermediateProvider":{"@xml:lang":"en","#text":"National and University Library of Slovenia"},"edm:dataProvider":{"@xml:lang":"sl","#text":"Slovensko kemijsko društvo"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:doc-3Y2E560Y/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:doc-3Y2E560Y"}}}}