Search

Your search keyword '"Kertesz, Miklos"' showing total 519 results
Start Over Author "Kertesz, Miklos"
519 results on '"Kertesz, Miklos"'

1. Extremely long C-C bonds predicted beyond 2.0 \r{A}

Author

Korpela, Eero J. J., Carvalho, Jhonatas, Lischka, Hans, and Kertesz, Miklos

Subjects
Physics - Chemical Physics
Abstract

A number of conjugated molecules are designed with extremely long single C-C bonds beyond 2.0 \r{A}. Some of the investigated molecules are based on analogs to the recently discovered molecule by Kubo et al. These bonds are analyzed by a variety of indices in addition to their equilibrium bond length including the Wiberg bond index, bond dissociation energy (BDE), and measures of diradicaloid character. All unrestricted DFT calculations indicate no diradical character supported by high-level multireference calculations. Finally, NFOD was computed through fractional orbital density (FOD) calculations and used to compare relative differences of diradicaloid character across twisted molecules without central C-C bonding and those with extremely elongated C-C bonds using a comparison with the C-C bond breaking in ethane. No example of direct C-C bonds beyond 2.4 \r{A} are seen in the computational modeling, however, extremely stretched C-C bonds in the vicinity of 2.2 \r{A} are predicted to be achievable with a BDE of 15-25 kcal/mol., Comment: This is a published paper to the J. Phys. Chem. A which I wanted to deposit to arXiv according to the instructions given by the journal. This file contains at the end a correction to a NSF grant number

Published
2023
Full Text
View/download PDF

5. Synchrony matters more than species richness in plant community stability at a global scale

Author

Valencia, Enrique, de Bello, Francesco, Galland, Thomas, Adler, Peter B., Lepš, Jan, E-Vojtkó, Anna, van Klink, Roel, Carmona, Carlos P., Danihelka, Jiří, Dengler, Jürgen, Eldridge, David J., Estiarte, Marc, García-González, Ricardo, Garnier, Eric, Gómez-García, Daniel, Harrison, Susan P., Herben, Tomáš, Ibáñez, Ricardo, Jentsch, Anke, Juergens, Norbert, Kertész, Miklós, Klumpp, Katja, Louault, Frédérique, Marrs, Rob H., Ogaya, Romà, Ónodi, Gábor, Pakeman, Robin J., Pardo, Iker, Pärtel, Meelis, Peco, Begoña, Peñuelas, Josep, Pywell, Richard F., Rueda, Marta, Schmidt, Wolfgang, Schmiedel, Ute, Schuetz, Martin, Skálová, Hana, Šmilauer, Petr, Šmilauerová, Marie, Smit, Christian, Song, MingHua, Stock, Martin, Val, James, Vandvik, Vigdis, Ward, David, Wesche, Karsten, Wiser, Susan K., Woodcock, Ben A., Young, Truman P., Yu, Fei-Hai, Zobel, Martin, and Götzenberger, Lars

Published
2020

8. Aggregation of One‐Dimensional Wires: The Case of Long Oligoynes.

Author

Gordillo‐Gámez, Fernando, Gao, Yueze, Aragó, Juan, Ortí, Enrique, Aranda, Daniel, Kertesz, Miklos, Tykwinski, Rik R., and Casado, Juan

Subjects
RAMAN spectroscopy, ABSORPTION spectra, INTERMOLECULAR interactions, LOW temperatures, PYRIDINE
Abstract

We show an unexpected aggregation phenomenon of a long oligoyne (Py[16]) with 16 contiguous triple bonds and endcapped with bulky 3,5‐bi(3,5‐bis‐tert‐butylphenyl)pyridine groups. Aggregation of 1D π‐conjugated oligoyne chains is rare given the minimal π–π intermolecular interactions as well as its flexibility that works against self‐assembly. In dilute solutions, the reversible aggregation of Py[16] initiates at low temperature in the range of 140–180 K, and is not observed for shorter oligoynes in this series. Cryogenic UV/Vis electronic absorption spectra and vibrational Raman spectra with different laser wavelength lines tuning from in‐resonance to off‐resonance conditions have been used to extract the vibrational features characterizing the monomer and aggregate species. Theoretical calculations complement the spectroscopic findings. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

11. Stakeholders’ perspectives on the operationalisation of the ecosystem service concept: Results from 27 case studies

Author

Dick, Jan, Turkelboom, Francis, Woods, Helen, Iniesta-Arandia, Irene, Primmer, Eeva, Saarela, Sanna-Riikka, Bezák, Peter, Mederly, Peter, Leone, Michael, Verheyden, Wim, Kelemen, Eszter, Hauck, Jennifer, Andrews, Chris, Antunes, Paula, Aszalós, Réka, Baró, Francesc, Barton, David N., Berry, Pam, Bugter, Rob, Carvalho, Laurence, Czúcz, Bálint, Dunford, Rob, Garcia Blanco, Gemma, Geamănă, Nicoleta, Giucă, Relu, Grizzetti, Bruna, Izakovičová, Zita, Kertész, Miklós, Kopperoinen, Leena, Langemeyer, Johannes, Montenegro Lapola, David, Liquete, Camino, Luque, Sandra, Martínez Pastur, Guillermo, Martin-Lopez, Berta, Mukhopadhyay, Raktima, Niemela, Jari, Odee, David, Peri, Pablo Luis, Pinho, Patricia, Patrício-Roberto, Gleiciani Bürger, Preda, Elena, Priess, Joerg, Röckmann, Christine, Santos, Rui, Silaghi, Diana, Smith, Ron, Vădineanu, Angheluţă, van der Wal, Jan Tjalling, Arany, Ildikó, Badea, Ovidiu, Bela, Györgyi, Boros, Emil, Bucur, Magdalena, Blumentrath, Stefan, Calvache, Marta, Carmen, Esther, Clemente, Pedro, Fernandes, João, Ferraz, Diogo, Fongar, Claudia, García-Llorente, Marina, Gómez-Baggethun, Erik, Gundersen, Vegard, Haavardsholm, Oscar, Kalóczkai, Ágnes, Khalalwe, Thalma, Kiss, Gabriella, Köhler, Berit, Lazányi, Orsolya, Lellei-Kovács, Eszter, Lichungu, Rael, Lindhjem, Henrik, Magare, Charles, Mustajoki, Jyri, Ndege, Charles, Nowell, Megan, Nuss Girona, Sergi, Ochieng, John, Often, Anders, Palomo, Ignacio, Pataki, György, Reinvang, Rasmus, Rusch, Graciela, Saarikoski, Heli, Smith, Alison, Soy Massoni, Emma, Stange, Erik, Vågnes Traaholt, Nora, Vári, Ágnes, Verweij, Peter, Vikström, Suvi, Yli-Pelkonen, Vesa, and Zulian, Grazia

Published
2018
Full Text
View/download PDF

12. Institutional challenges in putting ecosystem service knowledge in practice

Author

Saarikoski, Heli, Primmer, Eeva, Saarela, Sanna-Riikka, Antunes, Paula, Aszalós, Réka, Baró, Francesc, Berry, Pam, Blanko, Gemma Garcia, Goméz-Baggethun, Erik, Carvalho, Laurence, Dick, Jan, Dunford, Robert, Hanzu, Mihail, Harrison, Paula A., Izakovicova, Zita, Kertész, Miklós, Kopperoinen, Leena, Köhler, Berit, Langemeyer, Johannes, Lapola, David, Liquete, Camino, Luque, Sandra, Mederly, Peter, Niemelä, Jari, Palomo, Ignacio, Pastur, Guillermo Martinez, Peri, Pablo Luis, Preda, Elena, Priess, Jörg A., Santos, Rui, Schleyer, Christian, Turkelboom, Francis, Vadineanu, Angheluta, Verheyden, Wim, Vikström, Suvi, and Young, Juliette

Published
2018
Full Text
View/download PDF

16. Carbon Nanotube Actuators

Author

Baughman, Ray H., Cui, Changxing, Zakhidov, Anvar A., Iqbal, Zafar, Barisci, Joseph N., Spinks, Geoff M., Wallace, Gordon G., Mazzoldi, Alberto, De Rossi, Danilo, Rinzler, Andrew G., Jaschinski, Oliver, Roth, Siegman, and Kertesz, Miklos

Published
1999

20. Unraveling the dependence of proton transfer on solvent polarity in ion pairs of carbamates and dithiocarbamates with nitrogen‐based counterions.

Author

Poon, Louis, Hum, Jacob R., Kertesz, Miklos, and Weiss, Richard G.

Subjects
DITHIOCARBAMATES, ION pairs, CARBAMATES, PROTON affinity, PROTONS, AMIDINES
Abstract

Small, but important, differences in the structure–property relationships between ionomers composed of amidinium or imidazolinium groups with alkylcarbamate or alkyldithiocarbamate counterions have been examined experimentally by us previously. To unravel the sources of these differences, DFT calculations are conducted here for ion‐pair complexes (IPs) of these systems and their corresponding uncharged base and acid components (NPs). Calculations include IPs and NPs in which the amidine/amidinium and imidazoline/imidazolinium groups are anchored to a dimethylsiloxane pentamer. A surprising dependence of proton transfer on the dielectric constant (ε) of the medium is found for the systems: Whereas interconversion between the NPs and IPs is strongly dependent on medium dielectric in systems with an alkylcarbamate, none of the initial IP forms with an alkyldithiocarbamate transforms to an NP. Although the calculations do not include individual solvent–solute molecular interactions, they do probe how the components sense their bulk environments. The lack of detectable reversible proton transfer from the amidinium or imidazolinium cations to the dithiocarbamates is consistent with the "principle of proton affinity/pKa equivalence": Because the acidity of dithiocarbamates is higher than that of carbamates, the gap between their proton affinities (ΔPA) is decreased, favoring stronger electrostatic‐based H‐bonds in the ion‐pair complexes of the dithiocarbamates. The differences can also be estimated from the Deuri–Phukan nucleophilicity index scale, which is based on DFT calculations and suggests a strong dependence of proton transfer on the nucleophilicity of the base and the dielectric constant of the solvent. Predictions from these calculations on some important experimental systems are mentioned. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

24. Extremely long C-C bonds predicted beyond 2.0 Å

Author

Korpela, Eero J. J., Carvalho, Jhonatas, Lischka, Hans, and Kertesz, Miklos

Subjects
Chemical Physics (physics.chem-ph), FOS: Physical sciences
Abstract

A number of conjugated molecules are designed with extremely long single C-C bonds beyond 2.0 Å. Some of the investigated molecules are based on analogs to the recently discovered molecule by Kubo et al. These bonds are analyzed by a variety of indices in addition to their equilibrium bond length including the Wiberg bond index, bond dissociation energy (BDE), and measures of diradicaloid character. All unrestricted DFT calculations indicate no diradical character supported by high-level multireference calculations. Finally, NFOD was computed through fractional orbital density (FOD) calculations and used to compare relative differences of diradicaloid character across twisted molecules without central C-C bonding and those with extremely elongated C-C bonds using a comparison with the C-C bond breaking in ethane. No example of direct C-C bonds beyond 2.4 Å are seen in the computational modeling, however, extremely stretched C-C bonds in the vicinity of 2.2 Å are predicted to be achievable with a BDE of 15-25 kcal/mol., This is a published paper to the J. Phys. Chem. A which I wanted to deposit to arXiv according to the instructions given by the journal. This file contains at the end a correction to a NSF grant number

Published
2023
Full Text
View/download PDF

27. The generality of the GUGA MRCI approach in COLUMBUS for treating complex quantum chemistry.

Author

Lischka, Hans, Shepard, Ron, Müller, Thomas, Szalay, Péter G., Pitzer, Russell M., Aquino, Adelia J. A., Araújo do Nascimento, Mayzza M., Barbatti, Mario, Belcher, Lachlan T., Blaudeau, Jean-Philippe, Borges, Itamar, Brozell, Scott R., Carter, Emily A., Das, Anita, Gidofalvi, Gergely, González, Leticia, Hase, William L., Kedziora, Gary, Kertesz, Miklos, and Kossoski, Fábris

Subjects
SURFACE dynamics, COMPLEX compounds, ELECTRON configuration, COMPUTER workstation clusters, VIBRONIC coupling, SPIN-orbit interactions, QUANTUM chemistry
Abstract

The core part of the program system COLUMBUS allows highly efficient calculations using variational multireference (MR) methods in the framework of configuration interaction with single and double excitations (MR-CISD) and averaged quadratic coupled-cluster calculations (MR-AQCC), based on uncontracted sets of configurations and the graphical unitary group approach (GUGA). The availability of analytic MR-CISD and MR-AQCC energy gradients and analytic nonadiabatic couplings for MR-CISD enables exciting applications including, e.g., investigations of π-conjugated biradicaloid compounds, calculations of multitudes of excited states, development of diabatization procedures, and furnishing the electronic structure information for on-the-fly surface nonadiabatic dynamics. With fully variational uncontracted spin-orbit MRCI, COLUMBUS provides a unique possibility of performing high-level calculations on compounds containing heavy atoms up to lanthanides and actinides. Crucial for carrying out all of these calculations effectively is the availability of an efficient parallel code for the CI step. Configuration spaces of several billion in size now can be treated quite routinely on standard parallel computer clusters. Emerging developments in COLUMBUS, including the all configuration mean energy multiconfiguration self-consistent field method and the graphically contracted function method, promise to allow practically unlimited configuration space dimensions. Spin density based on the GUGA approach, analytic spin-orbit energy gradients, possibilities for local electron correlation MR calculations, development of general interfaces for nonadiabatic dynamics, and MRCI linear vibronic coupling models conclude this overview. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

43. Linear [C.sub.n] clusters: are they acetylenic or cumulenic?

Author

Shujiang Yang and Kertesz, Miklos

Subjects
Clusters (Chemistry) -- Observations, Clusters (Chemistry) -- Properties, Carbon compounds -- Research, Carbon compounds -- Properties, Chemicals, plastics and rubber industries
Abstract

The properties of long linear carbon clusters are investigated. A transition for long linear [C.sub.n] chains from essentially nonalternating cumulenic structures to bond length alternating acetylenic structures is observed.

Published
2008

44. Application of a novel linear/exponential hybrid force field scaling scheme to the longitudinal Raman active mode of polyyne

Author

Shujiang Yang, Kertesz, Miklos, Zolyomi, Viktor, and Kurti, Jeno

Subjects
Carbon compounds -- Structure, Carbon compounds -- Chemical properties, Raman effect -- Research, Nanotubes -- Structure, Nanotubes -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

The quantum mechanical calculations are used to investigate the Raman active longitudinal optical (LO) stretching vibrational modes of linear carbon chains. The results have provided evidence for the assignment of the characteristic Raman peaks near 1850 [cm.sup.-1] of the long linear carbon chains encapsulated inside multiwalled or double-walled carbon nanotubes.

Published
2007

47. Structure of burkeite and a new crystalline species obtained from solutions of sodium carbonate and sodium sulfate

Author

Shi, Bing, Rousseau, Ronald W., Kertesz, Miklos, Baughman, Ray H., Post, Michael, Jakubek, Zygmunt J., Deslandes, Yves, and Simard, Benoit

Subjects
Sodium compounds -- Research, Sodium compounds -- Atomic properties, Chemistry, Physical and theoretical -- Research, Chemicals, plastics and rubber industries
Abstract

Crystallization from aqueous solutions containing sodium carbonate and sodium sulfate can produce crystals of a double salt commonly known as burkeite. The maximum ratio of carbonate to sulfate in burkeite crystals was shown to be 1:1, and this limitation was explained by examination of the lattice structure of burkeite.

Published
2003

48. Variations of the geometries and band gaps of single-walled carbon nanotubes and the effect of charge injection

Author

Sun, Guangyu, Kurti, Jeno, Kertesz, Miklos, Baughman, Ray H., Simard, Benoit, Jakubek, Zygmunt J., Deslandes, Yves, and Post, Michael

Subjects
Carbon -- Research, Carbon -- Atomic properties, Density functionals -- Usage, Nanotubes -- Usage, Chemistry, Physical and theoretical -- Research, Chemicals, plastics and rubber industries
Abstract

The geometries of neutral and charged carbon single-walled nanotubes (SWNTs) are calculated using density functional theory. Different zigzag nanotubes with n=3i, 3i+1 and 3i+2 show different dimensional changes upon the injection of small charge (0.01 e per carbon atom), and the dimensional changes approach that of graphite when the tube diameter increases.

Published
2003

50. Dimensional changes as a function of charge injection in single-walled carbon nanotubes

Author

Guangyu Sun, Kurti, Jeno, Kertesz, Miklos, and Baughman, Ray H.

Subjects
Density functionals -- Research, Nanotubes -- Research, Carbon -- Chemical properties, Chemistry
Abstract

The dimensional changes in a nanotube are described as a function of charge injection for single-walled carbon nanotubes. It is concluded that density functional theory approach is highly reliable when the amount of charge injection is small.

Published
2002

Catalog

Books, media, physical & digital resources
See catalog results