High temperature thermodynamic studies of some gaseous thorium fluorides

Lau, K. H.; Brittain, R. D.; Hildenbrand, D. L.

doi:10.1063/1.456171

Cited by 55 publications

(41 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As has been noted in other work, 77 the BDEs of ThF 4 are all relatively similar and that is certainly exhibited in Table VI of 64 presumably mostly due to the larger basis sets (and extrapolation to the CBS limit) of this work and the use of a different PP on Th.…”

Section: Bond Dissociation Energies Of Thf 4 and Thfsupporting

confidence: 85%

Correlation consistent basis sets for actinides. I. The Th and U atoms

Peterson

2015

The Journal of Chemical Physics

149

189

View full text Add to dashboard Cite

New correlation consistent basis sets based on both pseudopotential (PP) and all-electron Douglas-Kroll-Hess (DKH) Hamiltonians have been developed from double- to quadruple-zeta quality for the actinide atoms thorium and uranium. Sets for valence electron correlation (5f6s6p6d), cc - pV nZ - PP and cc - pV nZ - DK3, as well as outer-core correlation (valence + 5s5p5d), cc - pwCV nZ - PP and cc - pwCV nZ - DK3, are reported (n = D, T, Q). The -PP sets are constructed in conjunction with small-core, 60-electron PPs, while the -DK3 sets utilized the 3rd-order Douglas-Kroll-Hess scalar relativistic Hamiltonian. Both series of basis sets show systematic convergence towards the complete basis set limit, both at the Hartree-Fock and correlated levels of theory, making them amenable to standard basis set extrapolation techniques. To assess the utility of the new basis sets, extensive coupled cluster composite thermochemistry calculations of ThFn (n = 2 - 4), ThO2, and UFn (n = 4 - 6) have been carried out. After accurately accounting for valence and outer-core correlation, spin-orbit coupling, and even Lamb shift effects, the final 298 K atomization enthalpies of ThF4, ThF3, ThF2, and ThO2 are all within their experimental uncertainties. Bond dissociation energies of ThF4 and ThF3, as well as UF6 and UF5, were similarly accurate. The derived enthalpies of formation for these species also showed a very satisfactory agreement with experiment, demonstrating that the new basis sets allow for the use of accurate composite schemes just as in molecular systems composed only of lighter atoms. The differences between the PP and DK3 approaches were found to increase with the change in formal oxidation state on the actinide atom, approaching 5-6 kcal/mol for the atomization enthalpies of ThF4 and ThO2. The DKH3 atomization energy of ThO2 was calculated to be smaller than the DKH2 value by ∼1 kcal/mol.

show abstract

Section: Bond Dissociation Energies Of Thf 4 and Thfsupporting

confidence: 85%

Correlation consistent basis sets for actinides. I. The Th and U atoms

Peterson

2015

The Journal of Chemical Physics

149

189

View full text Add to dashboard Cite

show abstract

“…The ThF dissociation energy is greater than the ionization energy [17,32], which may allow for greater flexibility in highly-efficient ion creation. One prospect is to prepare the neutral molecule in a core nonpenetrating high-l Rydberg state, where it can vibrationally autoionize without perturbing the ion core [42,43,44].…”

Section: Resultsmentioning

confidence: 99%

“…• C to obtain a sufficient vapor pressure of ThF 4 [31,32]. Initially, smaller diameters of quartz tubing were used but were rapidly blocked during operation.…”

Section: Frequency Comb Vmsmentioning

confidence: 99%

Broadband velocity modulation spectroscopy of ThF+ for use in a measurement of the electron electric dipole moment

Gresh

Cossel

Zhou

et al. 2016

Journal of Molecular Spectroscopy

View full text Add to dashboard Cite

A number of extensions to the Standard Model of particle physics predict a permanent electric dipole moment of the electron (eEDM) in the range of the current experimental limits. Trapped ThF + will be used in a forthcoming generation of the JILA eEDM experiment. Here, we present extensive survey spectroscopy of ThF + in the 700 -1000 nm spectral region, with the 700 -900 nm range fully covered using frequency comb velocity modulation spectroscopy. We have determined that the ThF + electronic ground state is X 3 ∆ 1 , which is the eEDM-sensitive state. In addition, we report high-precision rotational and vibrational constants for 14 ThF + electronic states, including excited states that can be used to transfer and readout population in the eEDM experiment.

show abstract

“…There are three studies on the vapour pressure of ThF 4 (s) and ThF 4 (l), performed by Darnell et al, 35 Lau et al 31 and Nagarajan et al 36 The composition of the vapour phase is very simple, consisting of only ThF 4 (g) in the monomeric form. The observed ions in the mass spectrum of the vapour effusing from the cell were Th + , ThF + , ThF 2 + and ThF 3 + and the appearance potentials of these ions, as measured in this work (Fig.…”

Section: Vapour Pressure Of Pure Thfmentioning

confidence: 99%

Determination of the thermodynamic activities of LiF and ThF₄in the Li_xTh_1−xF_4−3xliquid solution by Knudsen effusion mass spectrometry

Capelli

Beneš

Colle

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Knudsen effusion mass spectrometry (KEMS) has been used to investigate the vapour pressure over the molten LiF-ThF4 salt and determine the thermodynamic activity of LiF and ThF4 in the liquid solution. As part of the study, the vaporization of pure LiF and pure ThF4 was examined and the results were compared with the literature values finding a good agreement. Next, the vapour pressure of the LixTh1-xF4-3x liquid solution was investigated by measuring four samples having different compositions (XLiF∼ 0.2, 0.4, 0.6, 0.8 mol%). In order to determine the thermodynamic activities, the vapour pressure of LiF and ThF4 species over the liquid solution, as calculated from our results, were compared with the vapour pressure over the pure LiF(l) and pure ThF4(l) systems. A strong deviation from the Raoult's law was observed, more evident in case of LiF species, in agreement with the predictions by our thermodynamic model.

show abstract

High temperature thermodynamic studies of some gaseous thorium fluorides

Cited by 55 publications

References 15 publications

Correlation consistent basis sets for actinides. I. The Th and U atoms

Correlation consistent basis sets for actinides. I. The Th and U atoms

Broadband velocity modulation spectroscopy of ThF+ for use in a measurement of the electron electric dipole moment

Determination of the thermodynamic activities of LiF and ThF₄in the Li_xTh_1−xF_4−3xliquid solution by Knudsen effusion mass spectrometry

Contact Info

Product

Resources

About

High temperature thermodynamic studies of some gaseous thorium fluorides

Cited by 55 publications

References 15 publications

Correlation consistent basis sets for actinides. I. The Th and U atoms

Correlation consistent basis sets for actinides. I. The Th and U atoms

Broadband velocity modulation spectroscopy of ThF+ for use in a measurement of the electron electric dipole moment

Determination of the thermodynamic activities of LiF and ThF4in the LixTh1−xF4−3xliquid solution by Knudsen effusion mass spectrometry

Contact Info

Product

Resources

About

Determination of the thermodynamic activities of LiF and ThF₄in the Li_xTh_1−xF_4−3xliquid solution by Knudsen effusion mass spectrometry