  An efficient description of the structures of liquids and, in particular, the
structural changes that happen with liquids on supercooling remains to be a
challenge. The systems composed of soft particles are especially interesting in
this context because they often demonstrate non-trivial local orders that do
not allow to introduce the concept of the nearest-neighbor shell. For this
reason, the use of some methods, developed for the structure analysis of atomic
liquids, is questionable for the soft-particle systems. Here we report about
our investigations of the structure of the simple harmonic-repulsive liquid in
3D using the triple correlation function (TCF), i.e., the method that does not
rely on the nearest neighbor concept. The liquid is considered at reduced
pressure ($P=1.8$) at which it exhibits remarkable stability against
crystallization on cooling. It is demonstrated that the TCF allows addressing
the development of the orientational correlations in the structures that do not
allow drawing definite conclusions from the studies of the bond-orientational
order parameters. Our results demonstrate that the orientational correlations,
if measured by the heights of the peaks in the TCF, significantly increase on
cooling. This rise in the orientational ordering is not captured properly by
the Kirkwood's superposition approximation. Detailed considerations of the
peaks' shapes in the TCF suggest the existence of a link between the
orientational ordering and the slowdown of the system's dynamics. Our findings
support the view that the development of the orientational correlations in
liquids may play a significant role in the liquids' dynamics and that the
considerations of the pair distribution function may not be sufficient to
understand intuitively all the structural changes that happen with liquids on
supercooling.
