SPECTROSCOPIC CONSTANTS AND POTENTIAL-ENERGY CURVES OF 47 ELECTRONIC STATES OF INSB, INSB+, AND INSB-

Spectroscopic constants and potential energy curves of 26 electronic states of InSb, 12 electronic states of InSb+, and 9 electronic states of InSb_ are obtained using complete active space self-consistent field, first-order configuration interaction, second-order configuration interaction, and relativistic configuration interaction methods (CASSCF/FOCI/SOCI/RCI), including spin-orbit interaction. The SOCI calculations included up to 700 000 configurations. Spectroscopic constants obtained predict several allowed electronic transitions for InSb, InSb+, and InSb- which are yet to be observed. The ground states of InSb, InSb+, and InSb - are found to be X 3Τ0+-, X 4Σ1/2-, and X 2Σ 1/2+ with the constants InSb X 3Σ 0+- :Re = 3.02 Å, ωe = 121 cm-1, De = 1.35 eV; X 3Σ 1-: Re = 3.03 Å, ωe = 136 cm-1, Te = 494 cm-1; InSb+ X 4Σ1/2: Re = 3.351 Å, ωe = 63 cm-1, De = 0.37 eV; and InSb - X2Π3/2: Re = 2.695 Å, ωe = 191 cm-1, D0 = 2.5 eV. The adiabatic ionization potential and electron affinity of InSb are calculated as 6.33 and 1.41 eV, respectively. Analogous to the recently observed A 3Π-X 3Σ- system of GaAs, spectral bands in the 20 200 cm-1 region are predicted for InSb. Another 3Π(Π)- X3Σ- system is predicted at 15 830 cm-1. Both the 3Π states in these systems are found to be predissociated through crossing of a repulsive 5Σ- curve. The two low-lying electronic states of InSb- (2Σ+1/2 2Π1/2) undergo relativistic avoided crossing. © 1990 American Institute of Physics.