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Stability of the polyynic form of C18, C22, C26, and C30 nanorings: a challenge tackled by range-separated double-hybrid density functionals.
- Source :
- Physical Chemistry Chemical Physics (PCCP); 2/21/2022, Vol. 24 Issue 7, p4515-4525, 11p
- Publication Year :
- 2022
-
Abstract
- We calculate the relative energy between the cumulene and polyyne structures of a set of C<subscript>4k+2</subscript> (k = 4–7) rings (C<subscript>18</subscript>, C<subscript>22</subscript>, C<subscript>26</subscript>, and C<subscript>30</subscript> prompted by the recent synthesis of the cyclo[18]carbon (or simply C<subscript>18</subscript>) compounds. Reference results were obtained by a costly Quantum Monte-Carlo (QMC) approach, providing thus very accurate values allowing to systematically compare the performance of a variety of wavefunction methods [(i.e., MP2, SCS-MP2, SOS-MP2, DLPNO-CCSD, and DLPNO-CCSD(T)] as well as DFT approaches, applying for the latter a diversity of density functionals covering global and range-separated hybrid and double-hybrid models. The influence of the use of a range-separation scheme for density functionals, for both hybrid and double-hybrid expressions, is discussed according to its key role. Overall, range-separated double-hybrid functionals (e.g., RSX-QIDH) behave very accurately and provide competitive results compared with DLPNO-CCSD(T), at a more reasonable computational cost. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14639076
- Volume :
- 24
- Issue :
- 7
- Database :
- Complementary Index
- Journal :
- Physical Chemistry Chemical Physics (PCCP)
- Publication Type :
- Academic Journal
- Accession number :
- 155282127
- Full Text :
- https://doi.org/10.1039/d1cp04996h