@article {1283, title = {Avoided crossings between bound states of ultracold Cesium dimers}, journal = {Physical Review A}, volume = {78}, year = {2008}, month = {2008/11/5}, abstract = { We present an efficient new computational method for calculating the binding energies of the bound states of ultracold alkali-metal dimers in the presence of magnetic fields. The method is based on propagation of coupled differential equations and does not use a basis set for the interatomic distance coordinate. It is much more efficient than the previous method based on a radial basis set and allows many more spin channels to be included. This is particularly important in the vicinity of avoided crossings between bound states. We characterize a number of different avoided crossings in Cs_2 and compare our converged calculations with experimental results. Small but significant discrepancies are observed in both crossing strengths and level positions, especially for levels with l symmetry (rotational angular momentum L=8). The discrepancies should allow the development of improved potential models in the future. }, doi = {10.1103/PhysRevA.78.052703}, url = {http://arxiv.org/abs/0806.2583v1}, author = {Jeremy M. Hutson and Eite Tiesinga and Paul S. Julienne} }