  A two-component four-fermion system with equal masses, interspecies s-wave
scattering length a and vanishing intraspecies interactions under external
spherically symmetric harmonic confinement is considered. Using a correlated
Gaussian basis set expansion approach, we determine the energies and various
structural properties of the energetically lowest-lying gas-like state
throughout the crossover for various ranges of the underlying two-body
potential. Extrapolating to the zero-range limit, our numerical results show
explicitly that the total energy, the trap energy as well as certain aspects of
the pair distribution function and of the momentum distribution are related
through the so-called integrated contact intensity I(a). Furthermore, it is
shown explicitly that the total energy and the trap energy are related through
a generalized virial theorem that accounts for a non-zero range.
