Journal of Physical Studies 4(1), 16–22 (2000) DOI: https://doi.org/10.30970/jps.04.16 A POTENTIAL ENERGY OF INTERACTION BETWEEN HELIUM ATOMS

I. O. Vakarchuk, V. V. Babin, A. A. Rovenchak
Ivan Franko National University of Lviv, Department of Theoretical Physics
12 Drahomanov Str., UA-79005, Lviv, Ukraine

In the work the pair potential of interatomic interaction between helium atoms is established from the first principles without using fitting parameters. Previously obtained from Schrödinger equation connection between the potential Fourier image and the coefficient functions in the expansion of the many-boson system ground state wave function logarithm by the ‟degrees” of density fluctuations are used. RPA as the zero approximation and the approximation of ‟two sums over wave vector” as the first one are considered. The results of this work lead to the value of the first sound velocity of $231\ {\rm m/s}$ while the experiment gives $237\ {\rm m/s}$. The fit of our potential with Aziz model potential is quite good: the well depths are $-10.58$~K and $-11.04$~K respectively, the minimum positions being $3.34$~\AA{} and $2.99$~\AA.

ps pdf