  We present a program in C that employs spectral distribution theory for
studies of characteristic properties of a many-particle quantum-mechanical
system and the underlying few-body interaction. In particular, the program
focuses on two-body nuclear interactions given in a JT-coupled harmonic
oscillator basis and calculates correlation coefficients, a measure of
similarity of any two interactions, as well as Hilbert-Schmidt norms specifying
interaction strengths. An important feature of the program is its ability to
identify the monopole part (centroid) of a 2-body interaction, as well as its
'density-dependent' one-body and two-body part, thereby providing key
information on the evolution of shell gaps and binding energies for larger
nuclear systems. As additional features, we provide statistical measures for
'density-dependent' interactions, as well as a mechanism to express an
interaction in terms of two other interactions. This, in turn, allows one to
identify, e.g., established features of the nuclear interaction (such as
pairing correlations) within a general Hamiltonian. The program handles the
radial degeneracy for 'density-dependent' one-body interactions and together
with an efficient linked list data structure, facilitates studies of nuclear
interactions in large model spaces that go beyond valence-shell applications.
