TY - JOUR
T1 - Optical Stark and Zeeman Spectroscopy of Thorium Fluoride (ThF) and Thorium Chloride (ThCl)
AU - Nguyen, Duc Trung
AU - Steimle, Timothy
AU - Linton, Colan
AU - Cheng, Lan
N1 - Funding Information:
The research at Arizona State University was supported by a grant from the DoE - Heavy Elements Program (DESC0018241). We thank Prof. Michael Heaven (Emory University) for his insightful comments.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/2/21
Y1 - 2019/2/21
N2 - Experimentally and theoretically determined magnetic and electric dipole moments, bond distances, and vibrational spacings are used for a comparative study of the bonding in ThF and ThCl. Numerous bands in the visible electronic spectra between 16 400 and 18 800 cm -1 of supersonically cooled molecular beam samples have been detected using medium-resolution (0.1 cm -1 ) 2D spectroscopy. High-resolution (δ 1/2< 20 MHz) field-free, Stark, and Zeeman spectroscopy of the detected [18.6]ω = 3/2 - X 2 δ 3/2 band of ThF near 538.4 nm and the [18.2]ω = 3/2 - X 2 δ 3/2 band of ThCl near 551.0 nm have been recorded and analyzed. Stark shifts and splitting were analyzed to produce |μ→ el | values of 1.453(7) D and 0.588(9) D for the X 2 δ 3/2 and [18.6]ω = 3/2 states of ThF, respectively, and 2.022(35) D and 3.020(55) D for the X 2 δ 3/2 and [18.2]ω = 3/2 states of ThCl. Zeeman splittings and shifts were analyzed to produce g e values of 1.038(4) and 1.079(4) for the X 2 δ 3/2 and [18.6]ω = 3/2 states of ThF and 1.130(4) and 1.638(4) for the X 2 δ 3/2 and [18.2]ω = 3/2 states of ThCl. Analysis of g e values demonstrates that the X 2 δ 3/2 and [18.6]ω = 3/2 states of ThF and the X 2 δ 3/2 state of ThCl are predominately 2 δ 3/2 spin-orbit components, whereas the [18.2]ω = 3/2 state of ThCl is an admixture of 2 δ 3/2 and 2 3/2 spin-orbit components. A molecular orbital description of the ground states is used to rationalize the observed |μ→ - el |values for the ThX (X = F, Cl, O, and S) series and garner insight into the bonding mechanism. The dipole moments in the ground state of ThF and ThCl have been calculated using relativistic coupled-cluster methods. It is demonstrated that the systematic inclusion of electron-correlation contributions plays an essential role in obtaining accurate predictions for the dipole-moment values in ThF and ThCl.
AB - Experimentally and theoretically determined magnetic and electric dipole moments, bond distances, and vibrational spacings are used for a comparative study of the bonding in ThF and ThCl. Numerous bands in the visible electronic spectra between 16 400 and 18 800 cm -1 of supersonically cooled molecular beam samples have been detected using medium-resolution (0.1 cm -1 ) 2D spectroscopy. High-resolution (δ 1/2< 20 MHz) field-free, Stark, and Zeeman spectroscopy of the detected [18.6]ω = 3/2 - X 2 δ 3/2 band of ThF near 538.4 nm and the [18.2]ω = 3/2 - X 2 δ 3/2 band of ThCl near 551.0 nm have been recorded and analyzed. Stark shifts and splitting were analyzed to produce |μ→ el | values of 1.453(7) D and 0.588(9) D for the X 2 δ 3/2 and [18.6]ω = 3/2 states of ThF, respectively, and 2.022(35) D and 3.020(55) D for the X 2 δ 3/2 and [18.2]ω = 3/2 states of ThCl. Zeeman splittings and shifts were analyzed to produce g e values of 1.038(4) and 1.079(4) for the X 2 δ 3/2 and [18.6]ω = 3/2 states of ThF and 1.130(4) and 1.638(4) for the X 2 δ 3/2 and [18.2]ω = 3/2 states of ThCl. Analysis of g e values demonstrates that the X 2 δ 3/2 and [18.6]ω = 3/2 states of ThF and the X 2 δ 3/2 state of ThCl are predominately 2 δ 3/2 spin-orbit components, whereas the [18.2]ω = 3/2 state of ThCl is an admixture of 2 δ 3/2 and 2 3/2 spin-orbit components. A molecular orbital description of the ground states is used to rationalize the observed |μ→ - el |values for the ThX (X = F, Cl, O, and S) series and garner insight into the bonding mechanism. The dipole moments in the ground state of ThF and ThCl have been calculated using relativistic coupled-cluster methods. It is demonstrated that the systematic inclusion of electron-correlation contributions plays an essential role in obtaining accurate predictions for the dipole-moment values in ThF and ThCl.
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U2 - 10.1021/acs.jpca.8b11853
DO - 10.1021/acs.jpca.8b11853
M3 - Article
C2 - 30668099
AN - SCOPUS:85061546989
SN - 1089-5639
VL - 123
SP - 1423
EP - 1433
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 7
ER -