ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Resonant two-photon ionization spectra of LiCa have been obtained from a laser vaporization, supersonic expansion source. The ground state of the molecule is confirmed to be X 2Σ+. Three band systems have been observed near 15 282, 19 310, and 22 250 cm−1 and the upper states have been assigned as 2Σ+, 2Πr, and, tentatively, 2Π. Bond lengths and vibrational frequencies are reported for 7Li40Ca for the various states as X 2Σ+: r0=3.3796(11) Å, ΔG1/2=195.2 cm−1; 2Σ+: r0=3.4275(47) Å, ΔG1/2=283.5 cm−1; 2Πr: re=3.5451(36) Å, ωe=144.5 cm−1; and 2Π: ωe=178.53(5) cm−1. The ionization energy was also measured to be 4.471(1) eV by observing the onset of one-photon ionization. Results of ab initio all-electron calculations on twelve low-lying states [2Σ+(1), 2Σ+(2), 2Σ+(3), 2Σ+(4), 4Σ+(1), 4Σ−(1), 2Π(1), 2Π(2), 2Π(3), 2Π(4), 4Π(1), and 4Π(2)] are also reported, along with results on the X 1Σ+ ground electronic state of LiCa+. The dissociation energies of LiCa(X 2Σ+) into Li(2S)+Ca(1S) and of LiCa+ (X 1Σ+) into Li+(1S)+Ca(1S) are calculated to be 0.24 and 1.20 eV respectively, and the vertical and adiabatic ionization energies of LiCa have been determined to be almost the same, 4.43 eV, at the quadratic configuration interaction, including singles and doubles with approximate triples and all correlated electrons [QCISD(T,FULL)] level of theory. © 1998 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.477317
Permalink
