TY - JOUR
T1 - The pure rotational spectrum of ruthenium monocarbide, RuC, and relativistic ab initio predictions
AU - Wang, Fang
AU - Steimle, Timothy
AU - Adam, Allan G.
AU - Cheng, Lan
AU - Stanton, John F.
PY - 2013/11/7
Y1 - 2013/11/7
N2 - The J = 1 ← J = 0 and J = 2 ← J = 1 rotational transitions of ruthenium monocarbide, RuC, have been recorded using the separated field pump/probe microwave optical double resonance technique and analyzed to determine the fine and hyperfine parameters for the X1Σ + state. The 101Ru(I = 5/2) electric quadrupole parameter, eq0Q, and nuclear spin-rotation interaction parameter, CIeff, were determined to be 433.19(8) MHz and -0.049(6) MHz, respectively. The equilibrium bond distance, re, was determined to be 1.605485(2) Å. Hartree-Fock and coupled-cluster calculations were carried out for the properties of the X1Σ+ state. Electron-correlation effects are pronounced for all properties studied. It is shown that (a) the moderate scalar-relativistic contribution to eq0Q is entirely due to the coupling between scalar-relativistic and electron-correlation effects, (b) the spin-free exact two-component theory in its one-electron variant offers a reliable and efficient treatment of scalar-relativistic effects, and (c) non-relativistic theory performs quite well for the prediction of C Ielec, provided that electron correlation is treated accurately.
AB - The J = 1 ← J = 0 and J = 2 ← J = 1 rotational transitions of ruthenium monocarbide, RuC, have been recorded using the separated field pump/probe microwave optical double resonance technique and analyzed to determine the fine and hyperfine parameters for the X1Σ + state. The 101Ru(I = 5/2) electric quadrupole parameter, eq0Q, and nuclear spin-rotation interaction parameter, CIeff, were determined to be 433.19(8) MHz and -0.049(6) MHz, respectively. The equilibrium bond distance, re, was determined to be 1.605485(2) Å. Hartree-Fock and coupled-cluster calculations were carried out for the properties of the X1Σ+ state. Electron-correlation effects are pronounced for all properties studied. It is shown that (a) the moderate scalar-relativistic contribution to eq0Q is entirely due to the coupling between scalar-relativistic and electron-correlation effects, (b) the spin-free exact two-component theory in its one-electron variant offers a reliable and efficient treatment of scalar-relativistic effects, and (c) non-relativistic theory performs quite well for the prediction of C Ielec, provided that electron correlation is treated accurately.
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U2 - 10.1063/1.4828458
DO - 10.1063/1.4828458
M3 - Article
AN - SCOPUS:84903369188
SN - 0021-9606
VL - 139
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 17
M1 - 174318
ER -