COSMO-RI-ADC(2) excitation energies and excited state gradients

2018 ◽  
Vol 20 (24) ◽  
pp. 16354-16363 ◽  
Author(s):  
Sarah Karbalaei Khani ◽  
Alireza Marefat Khah ◽  
Christof Hättig
Keyword(s):  
Excited State ◽  
Excitation Energies ◽  
Vertical Excitation ◽  
Vertical Excitation Energies

Evaluating vertical excitation energies and excited state analytic gradients in solution at COSMO-ADC(2).

scholarly journals Ab initio studies of two pyrimidine derivatives as possible photo-switch systems

Open Physics ◽  
2013 ◽  
Vol 11 (9) ◽  
Author(s):  
András Csehi ◽  
Clemens Woywod ◽  
Gábor Halász ◽  
Ágnes Vibók
Keyword(s):  
Excited State ◽  
Hydrogen Transfer ◽  
Covalent Bond ◽  
Excitation Energies ◽  
Complete Active Space ◽  
Vertical Excitation ◽  
Singlet States ◽  
Self Consistent Field ◽  
Intramolecular Hydrogen ◽  
Vertical Excitation Energies

AbstractThe six lowest lying electronic singlet states of 8-(pyrimidine-2-yl)quinolin-ol and 2-(4-nitropyrimidine-2-yl)ethenol have been studied theoretically using the complete active space self-consistent-field (CASSCF) and M’ller-Plesset second-order perturbation theory (MP2) methods. Both molecules can be viewed as consisting of a frame and a crane component. As a possible mechanism for the excited-state relaxation process an intramolecular hydrogen transfer promoted by twisting around the covalent bond connecting the molecular frame and crane moieties has been considered. Based on this idea we have attempted to derive abstracted photochemical pathways for both systems. Geometry optimizations for the construction of hypothetical reaction coordinates have been performed at the MP2 level of theory while the CASSCF approach has been employed for the calculation of vertical excitation energies along the pathways. The results of the calculations along the specific twisting displacements investigated in this study do not support the notion of substantial twisting activity upon excitation of any of the five excited states at the planar terminal structures of the torsion coordinates of both molecules. However, the present analysis should be considered only as a first, preliminary step towards an understanding of the photochemistry of the two candidate compounds. For example, we have not performed any excited state geometry optimizations so far and the estimates of vertical excitation energies do not take dynamical electron correlation into account. Further work on this subject is in progress.

scholarly journals Benchmarking Density Functional Approximations for Excited-State Properties of Fluorescent Dyes

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7434
Author(s):  
Anna M. Grabarz ◽  
Borys Ośmiałowski
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Fluorescent Dyes ◽  
Dipole Moments ◽  
Photophysical Properties ◽  
Excitation Energies ◽  
Data Set ◽  
Vertical Excitation ◽  
A Minor ◽  
Vertical Excitation Energies

This study presents an extensive analysis of the predictive power of time-dependent density functional theory in determining the excited-state properties of two groups of important fluorescent dyes, difluoroboranes and hydroxyphenylimidazo[1,2-a]pyridine derivatives. To ensure statistically meaningful results, the data set is comprised of 85 molecules manifesting diverse photophysical properties. The vertical excitation energies and dipole moments (in the electronic ground and excited states) of the aforementioned dyes were determined using the RI-CC2 method (reference) and with 18 density functional approximations (DFA). The set encompasses DFAs with varying amounts of exact exchange energy (EEX): from 0% (e.g., SVWN, BLYP), through a medium (e.g., TPSSh, B3LYP), up to a major contribution of EEX (e.g., BMK, MN15). It also includes range-separated hybrids (CAM-B3LYP, LC-BLYP). Similar error profiles of vertical energy were obtained for both dye groups, although the errors related to hydroxyphenylimidazopiridines are significantly larger. Overall, functionals including 40–55% of EEX (SOGGA11-X, BMK, M06-2X) ensure satisfactory agreement with the reference vertical excitation energies obtained using the RI-CC2 method; however, MN15 significantly outperforms them, providing a mean absolute error of merely 0.04 eV together with a very high correlation coefficient (R2 = 0.98). Within the investigated set of functionals, there is no single functional that would equally accurately determine ground- and excited-state dipole moments of difluoroboranes and hydroxyphenylimidazopiridine derivatives. Depending on the chosen set of dyes, the most accurate μGS predictions were delivered by MN15 incorporating a major EEX contribution (difluoroboranes) and by PBE0 containing a minor EEX fraction (hydroxyphenylimidazopiridines). Reverse trends are observed for μES, i.e., for difluoroboranes the best results were obtained with functionals including a minor fraction of EEX, specifically PBE0, while in the case of hydroxyphenylimidazopiridines, much more accurate predictions were provided by functionals incorporating a major EEX contribution (BMK, MN15).

Excited states of acrolein: abinitio model studies on α,β-unsaturated carbonyl compounds

1982 ◽  
Vol 60 (5) ◽  
pp. 601-606 ◽  
Author(s):  
Katherine Valenta ◽  
Friedrich Grein
Keyword(s):  
Excited State ◽  
Excited States ◽  
Carbonyl Compound ◽  
Carbonyl Compounds ◽  
Excitation Energies ◽  
Vertical Excitation ◽  
Model Studies ◽  
Unsaturated Carbonyl Compound ◽  
Vertical Excitation Energies

As an explanation of the stereochemistry of photoaddition between α,β-unsaturated carbonyl compounds and olefins, Wiesner suggested that the excited state of the α,β-unsaturated carbonyl compound is pyramidal at the β-carbon. It is shown by abinitio SCF and CI studies that for acrolein in the 1nπ*, 3nπ*, and 3ππ* excited states the β-carbon remains planar. In addition, vertical excitation energies for the 1nπ* and 1ππ*, and adiabatic excitation energies for the 1nπ* and 3nπ* states of trans-acrolein have been calculated.

Exploring the Accuracy of a Low Scaling Similarity Transformed Equation of Motion Method for Vertical Excitation Energies

2017 ◽  
Vol 14 (1) ◽  
pp. 72-91 ◽  
Author(s):  
Achintya Kumar Dutta ◽  
Marcel Nooijen ◽  
Frank Neese ◽  
Róbert Izsák
Keyword(s):  
Equation Of Motion ◽  
Excitation Energies ◽  
Vertical Excitation ◽  
Motion Method ◽  
Vertical Excitation Energies

Vertical excitation energies for ribose and deoxyribose nucleosides

2007 ◽  
Vol 28 (11) ◽  
pp. 1776-1782 ◽  
Author(s):  
Remmick So ◽  
Saman Alavi
Keyword(s):  
Excitation Energies ◽  
Vertical Excitation ◽  
Vertical Excitation Energies

Assessment of n-Electron Valence State Perturbation Theory for Vertical Excitation Energies

2013 ◽  
Vol 9 (8) ◽  
pp. 3567-3580 ◽  
Author(s):  
Igor Schapiro ◽  
Kantharuban Sivalingam ◽  
Frank Neese
Keyword(s):  
Perturbation Theory ◽  
Valence State ◽  
Excitation Energies ◽  
Vertical Excitation ◽  
Vertical Excitation Energies
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