Heats of formation of LiOH(X1Σ+) and LiOH+(X2Π): the ionization energy of LiOH

RCCSD(T) calculations combined with large basis sets are employed to obtain the heats of formation of LiOH and LiOH+; in addition, the first adiabatic and vertical ionization energies of LiOH are obtained. Our best values are: ΔHf(LiOH, 0 K)=−57.0±−0.5 kcal mol−1 and D0=104±1 kcal mol−1. The ground state of LiOH+ is a quasilinear Renner–Teller X2Π state and AIE(LiOH)=8.91±0.03 eV. ΔHf(LiOH+, 0 K)=148±2 kcal mol−1 and D0=23±1 kcal mol−1. The proton affinity of LiO(X2Π) is derived as 230±1 kcal mol−1.