Applications of Diatomics-in-Molecules Theory. II. Prediction of a Stable Li3 Molecule

Diatomics-in-molecules theory applied to the Li3 molecule leads to the prediction of two forms stable with respect to Li2(1Σg+) + Li(2S) : a bent 2A1 state with an atomization energy at 0°K of 32.74 kcal/mole and an ionization energy of about 111 kcal/mole; a strongly bent 2B2 state with an atomization energy at 0°K of 30.34 kcal/mole. Potential-energy surfaces and fundamental vibrational frequencies are predicted for both states. Characteristics of the less stable linear conformation are discussed and compared with H3.