We request beamtime to study lithium silicate glasses over a very wide composition range from 20 to 65 mol.% Li2O, made by rapid quenching. For the higher Li2O contents, the glass is an invert glass, in which there is not a continuous, propagating SiO2 part to the network, so that Li2O must play the role of a glass former. We will investigate the lithium environment and its possible relationship to a change in behaviour in the density data. We will look for differences in the Li-O bond lengths for bridging and non-bridging oxygens. We will study the composition-dependence of the Si-O bond length, and determine the bond lengths for both bridging and non-bridging oxygens. This glass system is of structural interest, but the results may also be of interest in relation to the use of lithium containing glasses in battery applications.