Journal article
Accurate ab initio determination of the adiabatic potential energy function and the Born-Oppenheimer breakdown corrections for the electronic ground state of LiH isotopologues
The Journal of chemical physics, Vol.134(9), pp.094306-094306-14
03/03/2011
Handle:
https://hdl.handle.net/2376/109596
PMID: 21384968
Abstract
High level
ab initio
potential energy functions have been constructed for LiH in order to predict vibrational levels up to dissociation. After careful tests of the parameters of the calculation, the final adiabatic potential energy function has been composed from: (a) an
ab initio
nonrelativistic potential obtained at the multireference configuration interaction with singles and doubles level including a size-extensivity correction and quintuple-sextuple ζ extrapolations of the basis, (b) a mass-velocity-Darwin relativistic correction, and (c) a diagonal Born-Oppenheimer (BO) correction. Finally, nonadiabatic effects have also been considered by including a nonadiabatic correction to the kinetic energy operator of the nuclei. This correction is calculated from nonadiabatic matrix elements between the ground and excited electronic states. The calculated vibrational levels have been compared with those obtained from the experimental data [
J. A. Coxon
and
C. S. Dickinson
,
J. Chem. Phys.
134
,
9378
(
2004
)
]. It was found that the calculated BO potential results in vibrational levels which have root mean square (rms) deviations of about 6-7 cm
−1
for LiH and ∼3cm
−1
for LiD. With all the above mentioned corrections accounted for, the rms deviation falls down to ∼1cm
−1
. These results represent a drastic improvement over previous theoretical predictions of vibrational levels for all isotopologues of LiH.
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Details
- Title
- Accurate ab initio determination of the adiabatic potential energy function and the Born-Oppenheimer breakdown corrections for the electronic ground state of LiH isotopologues
- Creators
- Filip Holka - Groupe de Spectrométrie Moléculaire et Atmosphérique, Reims University, F-51687 Reims, FrancePéter Szalay - Groupe de Spectrométrie Moléculaire et Atmosphérique, Reims University, F-51687 Reims, FranceJulien Fremont - Groupe de Spectrométrie Moléculaire et Atmosphérique, Reims University, F-51687 Reims, FranceMichael Rey - Groupe de Spectrométrie Moléculaire et Atmosphérique, Reims University, F-51687 Reims, FranceKirk Peterson - Groupe de Spectrométrie Moléculaire et Atmosphérique, Reims University, F-51687 Reims, FranceVladimir Tyuterev - Groupe de Spectrométrie Moléculaire et Atmosphérique, Reims University, F-51687 Reims, France
- Publication Details
- The Journal of chemical physics, Vol.134(9), pp.094306-094306-14
- Academic Unit
- Chemistry, Department of
- Publisher
- American Institute of Physics
- Grant note
- TÁMOP 4.2.1./B-09/1/KMR-2010-0003 / EU F72423 / OTKA 1/0648/10 / VEGA
- Identifiers
- 99900547044701842
- Resource Type
- Journal article