  For the description of an H2 molecule an effective one-electron model
potential is proposed which is fully determined by the exact ionization
potential of the H2 molecule. In order to test the model potential and examine
its properties it is employed to determine excitation energies, transition
moments, and oscillator strengths in a range of the internuclear distances, 0.8
< R < 2.5 a.u. In addition, it is used as a description of an H2 target in
calculations of the cross sections for photoionization and for partial
excitation in collisions with singly-charged ions. The comparison of the
results obtained with the model potential with literature data for H2 molecules
yields a good agreement and encourages therefore an extended usage of the
potential in various other applications or in order to consider the importance
of two-electron and anisotropy effects.
