The heaviest group 2 difluoride, RaF2: geometry and ionization energy

The heaviest group 2 difluoride, RaF2: geometry and ionization energy

The heaviest group 2 difluoride, radium difluoride (RaF2), is studied for the first time. A basis set is employed for radium that combines an effective core potential with a large, flexible valence space. This basis set is tested by calculating the first and second ionization energies of Ra, where values in excellent agreement with experiment are obtained. MP2 ab initio calculations are employed to obtain the optimized equilibrium geometry and the harmonic vibrational frequencies for the ground-state neutral and some of the low-lying cationic states. In addition, the optimized geometry of the ground-state neutral is obtained at the CCSD(T) level. The trend in geometry of the group 2 difluorides is confirmed, with a angle ?FRaF bond angle of 118? degrees being calculated, together with a bond length of 2.30 ?. It is concluded that involvement of the Ra 6p orbitals in the valence molecular orbitals of RaF2 adequately explains its bent geometry. RCCSD(T) calculations are then employed to calculate ionization energies. The first adiabatic ionization energy, corresponding to the ionization X~2?u+?X~1A1 is calculated to be 10.67 +/- 0.05 eV. The ordering of the ionic states is discussed in the light of the present results. The polarizability of Ra was calculated to be 36.3 ?3, with that of Ra2+ was calculated to be 1.97 ?3; the latter was employed in a simple ionic model, but this failed to calculate the ionization energy accurately.

no+ cationic complexes, center-dot-no+, vibrational frequencies, electronic-structure, metal-halides, gas-phase, caf2, potentials, molecules, abinitio

5979-5984

Lee, Edmond P.F.

f47c6d5d-2d1f-4f03-a3ff-03658812d80b

Soldán, Pavel

a58f438f-bf0a-42bb-8efe-98c8d2eb6fbc

Wright, Timothy G.

20c2bf2d-6181-4571-9fdc-af171ad62cd5

5 November 2001

Lee, Edmond P.F.

f47c6d5d-2d1f-4f03-a3ff-03658812d80b

Soldán, Pavel

a58f438f-bf0a-42bb-8efe-98c8d2eb6fbc

Wright, Timothy G.

20c2bf2d-6181-4571-9fdc-af171ad62cd5

Lee, Edmond P.F., Soldán, Pavel and Wright, Timothy G.
(2001)
The heaviest group 2 difluoride, RaF2: geometry and ionization energy.
*Inorganic Chemistry*, 40 (23), .
(doi:10.1021/ic010538l).

## Abstract

The heaviest group 2 difluoride, radium difluoride (RaF2), is studied for the first time. A basis set is employed for radium that combines an effective core potential with a large, flexible valence space. This basis set is tested by calculating the first and second ionization energies of Ra, where values in excellent agreement with experiment are obtained. MP2 ab initio calculations are employed to obtain the optimized equilibrium geometry and the harmonic vibrational frequencies for the ground-state neutral and some of the low-lying cationic states. In addition, the optimized geometry of the ground-state neutral is obtained at the CCSD(T) level. The trend in geometry of the group 2 difluorides is confirmed, with a angle ?FRaF bond angle of 118? degrees being calculated, together with a bond length of 2.30 ?. It is concluded that involvement of the Ra 6p orbitals in the valence molecular orbitals of RaF2 adequately explains its bent geometry. RCCSD(T) calculations are then employed to calculate ionization energies. The first adiabatic ionization energy, corresponding to the ionization X~2?u+?X~1A1 is calculated to be 10.67 +/- 0.05 eV. The ordering of the ionic states is discussed in the light of the present results. The polarizability of Ra was calculated to be 36.3 ?3, with that of Ra2+ was calculated to be 1.97 ?3; the latter was employed in a simple ionic model, but this failed to calculate the ionization energy accurately.

Full text not available from this repository.

## More information

Published date: 5 November 2001

Keywords:
no+ cationic complexes, center-dot-no+, vibrational frequencies, electronic-structure, metal-halides, gas-phase, caf2, potentials, molecules, abinitio

## Identifiers

Local EPrints ID: 19543

URI: http://eprints.soton.ac.uk/id/eprint/19543

ISSN: 0020-1669

PURE UUID: 9f9a6b8d-fffb-49a6-ae3e-5bafcfbf6a47

## Catalogue record

Date deposited: 15 Feb 2006

Last modified: 15 Jul 2019 19:27

## Export record

## Altmetrics

## Contributors

Author:
Edmond P.F. Lee

Author:
Pavel Soldán

Author:
Timothy G. Wright

## University divisions

## Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics