Hydrogen atom in rotationally invariant noncommutative space
  We consider the noncommutative algebra which is rotationally invariant. The hydrogen atom is studied in a rotationally invariant noncommutative space. We find the corrections to the energy levels of the hydrogen atom up to the second order in the parameter of noncommutativity. The upper bound of the parameter of noncommutativity is estimated on the basis of the experimental results for 1s-2s transition frequency. 
Kh. P. Gnatenko, V. M. Tkachuk
quant-ph hep-th