  We study effects of the Pauli principle on the potential energy of
two-cluster systems. The object of the investigation is the lightest nuclei of
p-shell with a dominant $\alpha$-cluster channel. For this aim we construct
matrix elements of two-cluster potential energy between cluster oscillator
functions with and without full antisymmetrization. Eigenvalues and
eigenfunctions of the potential energy matrix are studied in detail.
Eigenfunctions of the potential energy operator are presented in oscillator,
coordinate and momentum spaces. We demonstrate that the Pauli principle affects
more strongly the eigenfunctions than the eigenvalues of the matrix and leads
to the formation of resonance and trapped states.
