Log in

Relevant bibliographies by topics / Restricted Open-Shell Kohn-Sham (ROKS)

Contents

Journal articles
Dissertations / Theses
Book chapters

Academic literature on the topic 'Restricted Open-Shell Kohn-Sham (ROKS)'

Author: Grafiati

Published: 2 November 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Restricted Open-Shell Kohn-Sham (ROKS).'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Restricted Open-Shell Kohn-Sham (ROKS)"

1

Schulte, Marius, and Irmgard Frank. "Restricted open-shell Kohn–Sham theory: N unpaired electrons." Chemical Physics 373, no. 3 (August 2010): 283–88. http://dx.doi.org/10.1016/j.chemphys.2010.05.031.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Büchel, Ralf, Luis Álvarez, Jan Grage, Dominykas Maniscalco, and Irmgard Frank. "On the Simulation of Photoreactions Using Restricted Open-Shell Kohn–Sham Theory." Molecules 29, no. 18 (September 23, 2024): 4509. http://dx.doi.org/10.3390/molecules29184509.

Full text

Abstract:

It is a well-established standard to describe ground-state chemical reactions at an ab initio level of multi-electron theory. Fast reactions can be directly simulated. The most widely used approach is density functional theory for the electronic structure in combination with molecular dynamics for the nuclear motion. This approach is known as ab initio molecular dynamics. In contrast, the simulation of excited-state reactions at this level of theory is significantly more difficult. It turns out that the self-consistent solution of the Kohn–Sham equations is not easily reached in excited-state simulations. The first program that solved this problem was the Car–Parrinello molecular dynamics code, using restricted open-shell Kohn–Sham theory. Meanwhile, there are alternatives, most prominently the Q-Chem code, which widens the range of applications. The present study investigates the suitability of both codes for the molecular dynamics simulation of excited-state motion and presents applications to photoreactions.

APA, Harvard, Vancouver, ISO, and other styles

3

Frank, Irmgard, and Konstantina Damianos. "Restricted open-shell Kohn-Sham theory: Simulation of the pyrrole photodissociation." Journal of Chemical Physics 126, no. 12 (March 28, 2007): 125105. http://dx.doi.org/10.1063/1.2711188.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Kowalczyk, Tim, Takashi Tsuchimochi, Po-Ta Chen, Laken Top, and Troy Van Voorhis. "Excitation energies and Stokes shifts from a restricted open-shell Kohn-Sham approach." Journal of Chemical Physics 138, no. 16 (April 28, 2013): 164101. http://dx.doi.org/10.1063/1.4801790.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Billeter, Salomon R., and Daniel Egli. "Calculation of nonadiabatic couplings with restricted open-shell Kohn-Sham density-functional theory." Journal of Chemical Physics 125, no. 22 (December 14, 2006): 224103. http://dx.doi.org/10.1063/1.2360261.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Nonnenberg, Christel, Christoph Bräuchle, and Irmgard Frank. "Restricted open-shell Kohn–Sham theory for π–π* transitions. III. Dynamics of aggregates." Journal of Chemical Physics 122, no. 1 (January 2005): 014311. http://dx.doi.org/10.1063/1.1829053.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Langer, Holger, and Nikos L. Doltsinis. "Excited state tautomerism of the DNA base guanine: A restricted open-shell Kohn–Sham study." Journal of Chemical Physics 118, no. 12 (March 22, 2003): 5400–5407. http://dx.doi.org/10.1063/1.1555121.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Nonnenberg, Christel, Stephan Grimm, and Irmgard Frank. "Restricted open-shell Kohn–Sham theory for π–π* transitions. II. Simulation of photochemical reactions." Journal of Chemical Physics 119, no. 22 (December 8, 2003): 11585–90. http://dx.doi.org/10.1063/1.1623743.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Filatov, Michael, and Sason Shaik. "Application of spin-restricted open-shell Kohn–Sham method to atomic and molecular multiplet states." Journal of Chemical Physics 110, no. 1 (January 1999): 116–25. http://dx.doi.org/10.1063/1.477941.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Grimm, Stephan, Christel Nonnenberg, and Irmgard Frank. "Restricted open-shell Kohn–Sham theory for π–π* transitions. I. Polyenes, cyanines, and protonated imines." Journal of Chemical Physics 119, no. 22 (December 8, 2003): 11574–84. http://dx.doi.org/10.1063/1.1623742.

Full text

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Restricted Open-Shell Kohn-Sham (ROKS)"

1

Grimm, Stephan. "Theoretische Untersuchung von pi-Bindungssystemen im Restricted Open Shell Kohn-Sham-Modell." Diss., lmu, 2005. http://nbn-resolving.de/urn:nbn:de:bvb:19-47476.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Grimm, Stephan Michael. "Theoretische Untersuchung von p-Bindungssystemen [Pi-Bindungssystemen] im Restricted-open-shell-Kohn-Sham-Modell." [S.l.] : [s.n.], 2005. http://edoc.ub.uni-muenchen.de/archive/00004747.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Diarra, Cheick Oumar. "Modélisation par dynamique moléculaire ab initio du transport des excitons et du transport thermique dans les semiconducteurs organiques pour la collecte d'énergie." Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAD013.

Full text

Abstract:

L'exciton joue un rôle clé dans le fonctionnement des cellules solaires organiques (OSCs). Comprendre sa dynamique dans les semiconducteurs organiques est essentiel, notamment pour améliorer la longueur de diffusion, une propriété déterminante pour la performance des hétérojonctions planaires, envisagées comme une alternative plus stable aux hétérojonctions en volume (BHJ). Dans la première partie de cette thèse, nous avons développé une approche méthodologique robuste et polyvalente pour évaluer la longueur de diffusion de l'exciton dans les semiconducteurs organiques. Cette approche, basée sur AIMD-ROKS, a été validée avec succès dans le cas du polymère P3HT. Elle a également été appliquée à l'accepteur NFA O-IDTBR, révélant des longueurs de diffusion prometteuses, mais encore insuffisantes pour les hétérojonctions planaires. Dans la deuxième partie de la thèse, le transfert de chaleur dans les semiconducteurs organiques a été exploré, élément crucial pour la performance des dispositifs thermoélectriques. Ces études se sont concentrées sur le P3HT, un matériau utilisé en thermoélectricité. Dans un premier temps, la conductivité thermique au sein des chaînes de P3HT a été étudiée, révélant l'influence de la longueur des chaînes de polymère. Ensuite, les transferts de chaleur entre ces chaînes ont également été examinés
The exciton plays a central role in the functioning of organic solar cells (OSCs). Understanding its dynamics in organic semiconductors is essential, particularly to optimize the diffusion length, a key property for the performance of planar heterojunctions, which are considered as a potentially more stable alternative to bulk heterojunctions (BHJ) in certain contexts. In the first part of this thesis, we developed a robust and versatile methodological approach to evaluate the exciton diffusion length in organic semiconductors. This method, based on AIMD-ROKS, was successfully validated for the P3HT polymer. It was also applied to the NFA O-IDTBR acceptor, revealing promising diffusion lengths, though still insufficient for planar heterojunctions. The second part of the thesis explores heat transfer in organic semiconductors, a crucial element for the performance of thermoelectric devices. These studies focused on P3HT, a material used in thermoelectricity. First, the thermal conductivity within P3HT chains was studied, revealing the influence of polymer chain length. Then, heat transfers between these chains were also examined

APA, Harvard, Vancouver, ISO, and other styles

4

Grimm, Stephan Michael [Verfasser]. "Theoretische Untersuchung von π-Bindungssystemen [Pi-Bindungssystemen] im Restricted-open-shell-Kohn-Sham-Modell / von Stephan Michael Grimm." 2005. http://d-nb.info/978848551/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Restricted Open-Shell Kohn-Sham (ROKS)"

1

Schautz, F., F. Buda, and C. Filippi. "Excitations in photoactive molecules from quantum Monte Carlo." In Quantum Monte Carlo, 145. Oxford University PressNew York, NY, 2007. http://dx.doi.org/10.1093/oso/9780195310108.003.00149.

Full text

Abstract:

Abstract Among the several quantum approaches to the accurate description of excitation processes in biological systems, the most promising candidates are: CASPT2, complete active space second-order perturbation theory; TDDFT, time-dependent density functional theory; ROKS, the restricted open-shell Kohn-Sham method; and QMC, quantum Monte Carlo. Each of these has its disadvantages. CASPT2 scales poorly with system size and is limited to smaller molecules. ROKS and TDDFT can be applied to very large systems but they may or may not be adequate for photoactive molecules. QMC scales favorably with system size but is computationally expensive. The authors address these issues in this paper with fixednode diffusion QMC calculations for ground and excited states for protypical photosensitive molecules, and companion calculations by CASPT2, TDDFT, and ROKS methods. The species chosen were formaldimine (CH2NH), formaldehyde (CH2O), and a protonated Schiff base (C5H6NH!) serving as a model for the retinal chromophore. The all-electron calculations were carried out with trial functions made up of linear combinations of Slater determinants, with Jastrow correlation factors optimized to minimize the average of energies for ground and excited states, using a fixed set of orbitals available for both. This was found to be important in obtaining accurate excitation energies. Transitions were examined along isomerization paths for each of the species, and comparisons of results were made for a variety of configurations.

APA, Harvard, Vancouver, ISO, and other styles

2

Autschbach, Jochen. "Self-consistent Field Orbital Methods." In Quantum Theory for Chemical Applications, 128–49. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190920807.003.0008.

Full text

Abstract:

This chapter discusses the concepts underlying the Hartree-Fock (HF) electronic structure method. First, it is shown how the energy expectation value is calculated for a Slater determinant (SD) wavefunction in the case of orthonormal orbitals. This leads to the definition of the electron repulsion integrals (ERIs). Next, the energy is minimized subject to the orthonormality constraints. This leads to the HF equation for the orbitals. The HF orbital energies are Langrange multipliers representing the constraints. An unknown set of orbitals can be determined from an initial guess via a self-consistent field (SCF) cycle. The HF scheme is discussed for closed-shell versus open shell systems, leading to the distinction between spin restricted and unrestricted HF (RHF, UHF). Kohn-Sham density functional theory (DFT) is introduced and its approximate version is placed in the context of ab-initio versus semi-empirical quantum chemistry methods.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!