## INTERACTION POTENTIAL BETWEEN ATOMS OF He

### Andrij Rovenchak

##### Ivan Franko National University of Lviv

In this work, the pair potential of interatomic interaction between
helium atoms is established from first principles without using
fitting parameters. Previously obtained from Schrodinger's
equation, is the connection between the potential Fourier image and
the coefficient functions. An expansion of the many-boson system
ground state wave function logarithm by the 'degrees' of density
fluctuations is 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 have lead to the value of the
first sound velocity bieng 231 m/s, while the experiment
gives 237 m/s. The fit of our potential with the Aziz model
potential is quite good: the well depths are -10.58 K and
-11.04 K respectively.

* Personal webpage *