Energy states of helium-4 dimer

It is shown that the binding energy of helium-4 dimer for the same class of potentials depends on the set of potential parameters used. The existence of one excited vibrational state of the dimer, which is related to one node of the radial wave function, is also proved for all used potentials. Excit ed state energy is about (-0,3 mK) . k(B). The expectation value of the int ernuclear distance is about 49 Angstrom in the ground state and 679 Angstro m in the excited state.