  We report Bose-Einstein condensation of weakly bound $^6$Li$_2$molecules in a
crossed optical trap near a Feshbach resonance. We measure a molecule-molecule
scattering length of$170^{+100}_{-60}$ nm at 770 G, in good agreement with
theory.We study the expansion of the cloud in the BEC-BCS crossoverregion.

Statistical Mechanics;Other Condensed Matter