MILLIMETER- AND SUBMILLIMETER-WAVE SPECTRA AND MOLECULAR CONSTANTS OF LIF AND LICL

High-precision measurements of many millimeter- and submillimeter-wave rotational lines of different isotopic species of lithium fluoride and chloride in four different vibrational states have provided accurate evaluation of their rotational, vibrational, and potential constants. The resulting values are: Y01 Y11 Y02 re ωe ωexe (Mc/sec) (Mc/sec) (kc/sec) () (cm-1) (cm-1) Li6F19 45 230.848 722.417 442.95 1.563 857 964.24 9.136 Li7F19 40 329.808 608.182 352.36 1.563 857 910.25 8.104 Li6Cl35 24 116.578 291.760 132.56 2.020 671 686.23 5.096 Li6Cl37 23 925.383 288.305 130.42 2.020 671 683.64 5.084 Li7Cl35 21 181.004 240.122 102.19 2.020 671 643.31 4.501 Li7Cl37 20 989.825 236.894 100.41 2.020 671 640.22 4.490 Be=h8π2μre2 is shown to differ from the observed value Y01 because of small isotopic effects. © 1969 The American Physical Society.