Assessment of density functional theory for bonds formed between rare gases and open-shell atoms: a computational study of small molecules containing He, Ar, Kr and Xe

Abstract

The validity of the description of the DFT approximations currently implemented in plane wave DFT codes (LDA, GGA, meta-GGA, hybrid, GGA + empirical dispersion correction) for interactions between rare gases and open-shell atoms which form materials is poorly known. We have performed a first assessment of the accuracy of these functionals for the description of the bonds formed by helium, argon, krypton and xenon with various open-shell atoms. This evaluation has been done on model molecular systems for which precise experimental data are available and reference post-Hartree-Fock calculations (CCSD(T) using large basis sets) are feasible. The results show that when the rare gas atom shares density with the neighbouring atoms, the GGA functionals yield good geometries and qualitatively correct binding energies, even if these are quite significantly overestimated. The use of hybrid functionals enables us to obtain good geometries and satisfactory binding energies. For compounds in which the rare gas atom forms weak dispersive-like bonding, the accuracy yielded by the various functionals is not as good. No functional gives satisfactory binding energies for all the compounds investigated. Several GGA and hybrid functionals yield correct geometries, even if some isomers are not obtained. One GGA functional (PBE) yields qualitatively correct results for the compounds of the three rare gases and several hybrid functionals give satisfactory energies for He compounds. The addition of an empirical dispersive correction improves the results on association compounds, but several isomers are not found.

First-principles study of rare gas incorporation in titanium nitride

“…This effect, which has a dominant contribution in the chemical interaction involving rare gas elements, is expected to be more important for the lightest (He) than for the heaviest (Xe) atom as a consequence of the largest polarizability of the heaviest atoms. 74 The so-called DFT-D2 Grimme approach, 75 which consists in adding a semiempirical dispersion potential to the conventional Kohn-Sham DFT energy and the van der Waals density functional (vdW-DF) approach 76 which considers the nonlocal interaction as a density-density interaction, are available in the recent release of the VASP code (version 5.2) in order to estimate the van der Waals interactions in a solid. An earlier version of VASP is used in this study, so the van der Waals contributions could not be estimated precisely.…”

“…At the phenomenological level, in a UO 2 crystal, Gryaznov et al 77 mentioned a van der Waals contribution of −0.25 eV to the He incorporation energy, taking into account a posteriori shell-model empirical potentials. Moreover, Bertolus et al 74 showed that, for the incorporation of rare gases in small molecules such as HeHCN and KrHCN, a relative error of several percent was found on their binding energy. In our case, the incorporation energies of helium are about several eV with a minimum of 1.13 eV for the I He V Ti case.…”

Linking atomic and mesoscopic scales for the modelling of the transport properties of uranium dioxide under irradiation

“…The validity of several types of functionals for the description of bonds formed by rare gases has also been assessed on model molecular compounds [37]. The results show that when the rare gas atom shares density with the neighbouring atoms, the GGA functionals yield good geometries and qualitatively correct binding energies, even if these are quite significantly overestimated.…”

DFT Study of the effects of counter ions on bonding, molecular and spectral properties of pentaflourophenyl xenonium diflouride cation

“…2,3 Among various noble gases, less attention has been made on the first two noble gases, helium and neon and some studies have been focused on the chemistry of argon [4][5][6] and krypton. [7][8][9][10] Since preparation, isolation and study of noble gas compounds are difficult, theoretical methods have been mostly used to anticipate the bonding, 11,12 formation 13 and properties 14,15 of these compounds. Some investigations have been focused on the theoretical study of all noble gases without considering a special noble gas.…”

“…38 In addition, the preparation and reactivity of compounds containing a carbon-xenon bond have been reviewed by Frohn. 39 Contrary to the large number of experimental and theoretical studies on organoxenons, [40][41][42][43][44][45][46][47][48][49] many potential molecules and their properties in this area are also unknown and research on the new organoxenon compounds seems to be interesting. One of them is the effect of counter ions on the stabilities and properties of organoxenon cations.…”