Scattering length of the ground-state Mg plus Mg collision

We have constructed the X (1)Sigma(g)(+) potential for the collision between two ground-state Mg atoms and analyzed the effect of uncertainties in the shape of the potential on scattering properties at ultracold temperatures. This potential reproduces the experimental term values to 0.2 cm(-1) and has a scattering length of +1.4(5) nm where the error is predominantly due to the uncertainty in the dissociation energy and the C-6 dispersion coefficient. A positive sign of the scattering length suggests that a Bose-Einstein condensate of ground-state Mg atoms is stable.