The potential scheme of LiCa from ab initio calculations (Ref. 2). At the atomic asymptote, first the electronic state of Li and then that of Ca is given. With thin (black and red) solid lines the 2Σ+ and 2Π states are shown, the thin (black and red) dashed lines correspond to 4Σ+ and 4Π states. The thick lines indicate the two doublet states studied in this paper and the quartet state which may predissociate the upper of these two doublet states. The doublet and quartet Δ states are not shown.
Fluorescence progression in LiCa and large extension by rotational satellites.
The range of vibrational and rotational quantum numbers of the observed levels in the X2Σ+ state of 7Li40Ca.
Level scheme of the observed transitions between the 42Σ+ and the X2Σ+ states. For simplicity, only two vibrational levels of the X state (with v″ and v″ + 1) are given. For the later discussion with Eqs. (3) and (4), two spacings between the F 1 levels are marked on the left side giving direct access to the spin-rotation interaction of the lower state.
Difference between the transition frequencies of the P and R lines of the vibrational progression ((v ′ = 8, N ′ = 45) → (v″, N ′′ = 44, 46)) for the F 1 and F 2 components (see Eq. (2) and the text).
(a) The averaged value of a ′′ as a function of v″ derived from Eq. (3). (b) Difference between the vibrational spacings Δν PP1 − Δν PP2 and Δν RR1 − Δν RR2 of progressions of N ′ = 45 according to Eq. (4). All the spacings are taken with respect to the transitions to v″ = 6.
The potential energy curve of the X2Σ+ state in LiCa. In the lower panel, the uncertainties of the pointwise potential for two values of the singularity parameter ξ are given (see the text for details).
Experimental LiCa ground state potential curve U(R) (left scale) and spin-rotation function γ(R) (right scale) from Table II and Eqs. (15) and (17), respectively, are shown as functions of internuclear distance as solid (black) line. The vertical dashed blue lines show the inner and outer turning points of the highest observed vibrational level; U(R) and γ(R) are well defined by experimental data only near the turning points and between them. The ab initio γ(R) curve is shown also as a dashed (red) line, in reasonable agreement with experiment.
Pointwise representation of the potential energy curve for the X2Σ+ state of LiCa. For interpolation, a natural cubic spline through all the listed points should be used (Ref. 18). The long-range expansion (Eq. (11)) starts at R o = 10.2692 Å.
Parameters of the analytic representation of the X state potential. The energy reference is the dissociation asymptote. Parameters with an asterisk (*) ensure smooth continuous extrapolation of the potential at .
Selected Dunham coefficients for 7Li40Ca in cm−1. See the supplementary material for the full list.25
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