Extensive Monte Carlo simulations of lithium oxide, Li2O, an important material for fusion applications over a wide range of temperatures have been performed. In the low temperature range 1 – 500 K, quantum corrections to the enthalpy and unit cell size were determined. We show that the classical Monte Carlo underestimates both these quantities and the difference between unit cell parameter with and without quantum corrections is large enough that such corrections should be included in any comparison between theory and experiment. Over the range 300 − 1000 K, the formation energy of Schottky and Frenkel defects are calculated, several possible diffusion mechanisms identified, and the migration energy of vacancy-mediated Li diffusion estimated. At temperatures above 1000 K, the superionic phase transition and subsequent melting are simulated.