Hydrogenic ions in an attosecond laser

We consider dynamics of a hydrogenic system in an ulktrashort laser pulse. In particular, we study a response of a 3D model system, represented by a smoothed form of the Coulomb potential that has the first moment of the error equal to zero and is exact at long range. This vanishing moment implies quite accurate expectation value of the potential and the local modification only affects dynamics close to the nucleus. The range of modification of the potential is defined by a cutoff parameter and this value can be optimized for a compromise between computational efficiency and the accuracy of the targeted observables, which is the subject of the present study.