The role of higher excitations in the quantum chemical description of molecules and radicals: method development and applications  Page description

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Details of project

  
Identifier
47182
Type K
Principal investigator Szalay, Péter
Title in Hungarian Magasabb gerjesztések figyelembevétele molekulák és gyökök kvantumkémiai leírása során: módszerfejlesztés és alkalmazás
Title in English The role of higher excitations in the quantum chemical description of molecules and radicals: method development and applications
Panel Chemistry 1
Department or equivalent Institute of Chemistry (Eötvös Loránd University)
Participants Kállay, Mihály
Starting date 2004-01-01
Closing date 2008-08-31
Funding (in million HUF) 5.487
FTE (full time equivalent) 0.00
state closed project





 

Final report

  
Results in Hungarian
A projekt keretében egyrészt kvantumkémiai módszereket fejlesztettük, másrészt felhasználtuk ezeket kémiailag érdekes rendszerek jellemzésére. Módszereket dolgoztunk ki és teszteltünk magasabb gerjesztések közelítő figyelembevételére a Coupled-Cluster elmélet keretében; továbbfejlesztettük multireferencia módszereinket (mint pl. MR-AQCC), eljárásokat dolgoztunk ki a Born-Oppenheimer közelítésen túlmutató korrekciók és csatolások számítására. Vizsgáltuk szubsztituált benzol kationokban fellépő vibronikus kölcsönhatásokat, a citozin molekula gerjesztett állapotait, valamint kis molekulák és gyökök nagyon pontos képződéshőit határoztuk meg (ún. HEAT eljárás).
Results in English
During the founding period we have developed quantum chemical methods and applied them to chemically interesting problems. New methods have been developed and tested for the approximate treatment of higher excitations in Coupled-Cluster theory; we have improved our multireference methods (like the MR-AQCC method); worked out new techniques to calculate corrections to the Born-Oppenheimer approximation. We have studied the vibronic effects in substituted benzene radical cations, excited states of cytosine, and obtained very accurate heat of formations for small molecules and radicals (HEAT method).
Full text http://real.mtak.hu/1721/
Decision
Yes





 

List of publications

  
P.G. Szalay, A. Tajti and J.F. Stanton: Ab initio determination of the heat of formation of ketenyl (HCCO) and ethynyl (CCH) radicals,, Mol. Phys. 103, 2159-2168, 2005
A. Tajti, P.G. Szalay, A.G. Császár, M. Kállay, J. Gauss, E.F. Valeev, B.A. Flowers, J. Vázquez, J.F. Stanton: HEAT: High Accuracy Extrapolated Ab initio Thermochemistry, J. Chem. Phys. 121, 11599, 2004
P.G. Szalay, J. Vázquez, Ch. Simmons and J.F. Stanton: Triplet Instability in doublet systems, J. Chem. Phys. 121, 7624, 2004
P.G. Szalay: Configuration Interaction: Correction for Size Consistency, Encyclopedia of Computational Chemistry, Wiley, 2005
Yannick J. Bomble, Jamal C. Saeh, John F. Stanton, Peter G. Szalay, Mihaly Kallay and Jurgen Gauss: Iterative approximate triples linear response coupled cluster methods for ionized states, J. Chem. Phys., 122, 154107, 2005
Yannick J. Bomble, John F. Stanton, Mihály Kállay and Jürgen Gauss: Coupled cluster methods including non-iterative approximate, J. Chem. Phys. 123, 054101, 2005
P. Neogrady, P.G. Szalay, W.P. Kraemer and M. Urban: Coupled Cluster Study of the Spectroscopic Constants of the Alkali Metal Diatomics: Ground and the Doublet Excited States of Na2, NaLi, NaK and NaR, Coll. Chech. Chem. Comm. 70, 951, 2005
Mihály Kállay and Jürgen Gauss: Approximate treatment of higher excitations in coupled-cluster theory, J. Chem. Phys. 123, 214105, 2005
M. Heckert, O. Heun, J. Gauss and P.G. Szalay: Spin-Adapted Coupled-Cluster Theory for High-Spin Open-Shell States quadruple excitation corrections, J. Chem. Phys. submitted for publication, 2005
M. Heckert, O. Heun, J. Gauss and P.G. Szalay: Spin-Adapted Coupled-Cluster Theory for High-Spin Open-Shell States, J. Chem. Phys. 124, 124105, 2006
Y.J. Bombele, J. Vázquez, M. Kállay, C. Michauk, P.G. Szalay, A.G. Császár, J. Gauss and J.F. Stanton: HEAT: High Accuracy Extrapolated Ab initio Thermochemistry. II. Minor improvements to the Protocol and a Vital Simplification, J. Chem. Phys. 125, 064108, 2006
I. Baldea, J. Franz, P.G. Szalay and H. Köppel: Multi-mode vibronic interactions in the five lowest electronic state of the flourobenzene radical cation, Chem. Phys. 329, 65-75, 2006
J. Gauss, A. Tajti, M. Kállay, J.F. Stanton and P.G Szalay: Analytic Calculation of the Diagonal Born-Oppenheimer Correction within Configuration-Interaction and Coupled-Cluster Theory, J. Chem. Phys. 125, 144111, 2006
A. Tajti, P.G Szalay and J. Gauss: Perturbative treatment of the electron-correlation contribution to the diagonal Born-Oppenheimer correction, J. Chem. Phys. 127, 014102, 2007
C. Angeli, G. L. Bendazzoli, S. Borini, R. Cimiraglia, A. Emerson, S. Evangelisti, D. Maynau, A. Monari, E. Rossi, J. Sanchez-Marin, P. G. Szalay, A. Tajti: The problem of interoperability: A common data format for quantum chemistry codes, Int. J. Quantum Chem., 107, 2082, 2007
R. Shepard, G.S. Kedziora, H. Lischka, I. Shavitt, T. Müller, P.G. Szalay, M. Kállay, M. Seth: The accuracy of molecular bond length computed by multireference electronic structure methods, Chem. Phys. 349, 37-57, 2008
P.G. Szalay: Multireference Averaged Quadratic Coupled-Cluster (MR-AQCC) method based on the functional of the total energy, Chem. Phys. 349, 121-125, 2008
A. Tajti, G. Fogarasi, P.G. Szalay: Excited states of cytosine: role of non-adiabatic effects, Int. J. Quant. Chem. beküldve, 2008



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