banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The X2Σ+ state of LiCa studied by Fourier-transform spectroscopy
Rent this article for


Image of FIG. 1.
FIG. 1.

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.

Image of FIG. 2.
FIG. 2.

Fluorescence progression in LiCa and large extension by rotational satellites.

Image of FIG. 3.
FIG. 3.

The range of vibrational and rotational quantum numbers of the observed levels in the X2Σ+ state of 7Li40Ca.

Image of FIG. 4.
FIG. 4.

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.

Image of FIG. 5.
FIG. 5.

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).

Image of FIG. 6.
FIG. 6.

(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.

Image of FIG. 7.
FIG. 7.

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).

Image of FIG. 8.
FIG. 8.

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.


Generic image for table
Table I.

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.

Generic image for table
Table II.

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 .

Generic image for table
Table III.

Selected Dunham coefficients for 7Li40Ca in cm−1. See the supplementary material for the full list.25


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: The X2Σ+ state of LiCa studied by Fourier-transform spectroscopy