RT info:eu-repo/semantics/article
T1 How accurate is the determination of equilibrium structures for van der Waals complexes? The dimer N2O⋯CO as an example
A1 Demaison, Jean
A1 Vogt, Natalja
A1 Jin, Yan
A1 Saragi, Rizalina Tama
A1 Juanes San José, Marcos
A1 Lesarri Gómez, Alberto Eugenio
K1 Intermolecular forces
K1 Fuerzas intermoleculares
K1 Ab-initio methods
K1 Métodos ab initio
AB Plausible methods for accurate determination of equilibrium structures of intermolecular clusters have been assessed for the van der Waals dimer N2O⋯CO. In order to assure a large initial dataset of rotational parameters, we first measured the microwave spectra of the 15N2O⋯12CO and 15N2O⋯13CO isotopologs, expanding previous measurements. Then, an anharmonic force field was calculated ab initio and a semi-experimental equilibrium structure was determined. The dimer structure was also calculated at the coupled-cluster level of theory using very large basis sets with diffuse functions and counterpoise correction. It was found that the contributions of the diffuse functions and the counterpoise correction are not additive and do not compensate each other although they have almost the same value but opposite signs. The semi-experimental and ab initio structures were found to be in fair agreement, with the equilibrium distance between the centers of mass of both monomers being 3.825(13) Å and the intermolecular bond length r(C⋯O) = 3.300(9) Å. In this case, the mass-dependent method did not permit us to determine reliable intermolecular parameters. The combination of experimental rotational constants and results of ab initio calculations thus proves to be very sensitive to examine the accuracy of structural determinations in intermolecular clusters, offering insight into other aggregates.
PB AIP Publishing
SN 1089-7690
YR 2021
FD 2021
LK https://uvadoc.uva.es/handle/10324/47814
UL https://uvadoc.uva.es/handle/10324/47814
LA eng
NO The Journal of Chemical Physics, 2021, vol. 154, n. 19. 12 p.
NO Producción Científica
DS UVaDOC
RD 07-dic-2021