  The Fourier component of the potential energy of interaction of an atom with
an atom is represented as a polynomial of the fourth degree from the atomic
form factor. A numerical calculation was performed for the atomic form factor
in the approximation of hydrogen-like wave functions. It is shown that taking
the Pauli principle into account leads to two local potential wells, which are
separated by a potential barrier. It was shown that this model gives
satisfactory agreement with the experiment in the depth of the potential well,
but its position and width differ from the results of the experiment with a
diatomic beryllium molecule (dimer). It is shown that the further approach of
two beryllium atoms leads to a new potential minimum, which could not be found
in the literature.
