Singlet L-a and L-b Bands for N-Acenes (N = 2-7): A CASSCF/CASPT2 Study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F17%3A00479628" target="_blank" >RIV/61388963:_____/17:00479628 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61989592:15310/17:73584870

Výsledek na webu

<a href="http://dx.doi.org/10.1021/acs.jctc.7b00302" target="_blank" >http://dx.doi.org/10.1021/acs.jctc.7b00302</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jctc.7b00302" target="_blank" >10.1021/acs.jctc.7b00302</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Singlet L-a and L-b Bands for N-Acenes (N = 2-7): A CASSCF/CASPT2 Study

Popis výsledku v původním jazyce

In this work CASPT2 calculations of polyacenes (from naphthalene to heptacene) were performed to find a methodology suitable for calculations of the absorption spectra, in particular of the La (B-2u state) and L-b (B-3u state) bands, of more extended systems. The effect of the extension of the active space and of freezing a orbitals was investigated. The MCSCF excitation energy of the B-2u state is not sensitive to the size of the active space used. However, the CASPT2 results depend strongly on the amount of a orbitals frozen reflecting the ionic character of the B-2u state. On the other hand, the excitation energies of the B-3u state are much more sensitive to the size of the active space used in the calculations reflecting its multiconfigurational character. We found a good agreement with experimental data for both bands by including 14 electrons in 14 pi orbitals in the active space followed by the CASPT2(14,14) perturbation scheme in which both sigma and pi orbitals are included.

Název v anglickém jazyce

Singlet L-a and L-b Bands for N-Acenes (N = 2-7): A CASSCF/CASPT2 Study

Popis výsledku anglicky

In this work CASPT2 calculations of polyacenes (from naphthalene to heptacene) were performed to find a methodology suitable for calculations of the absorption spectra, in particular of the La (B-2u state) and L-b (B-3u state) bands, of more extended systems. The effect of the extension of the active space and of freezing a orbitals was investigated. The MCSCF excitation energy of the B-2u state is not sensitive to the size of the active space used. However, the CASPT2 results depend strongly on the amount of a orbitals frozen reflecting the ionic character of the B-2u state. On the other hand, the excitation energies of the B-3u state are much more sensitive to the size of the active space used in the calculations reflecting its multiconfigurational character. We found a good agreement with experimental data for both bands by including 14 electrons in 14 pi orbitals in the active space followed by the CASPT2(14,14) perturbation scheme in which both sigma and pi orbitals are included.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA16-16959S" target="_blank" >GA16-16959S: Teoretický popis elektronicky excitovaných stavů kovalentně a nekovalentně funkcializovaných grafenů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Chemical Theory and Computation

ISSN

1549-9618

e-ISSN

—

Svazek periodika

13

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

4297-4306

Kód UT WoS článku

000410867500031

EID výsledku v databázi Scopus

2-s2.0-85029222760