  7Li NMR spectra were measured in a magnetic field up to 17 T at temperatures
5-30 K on single crystalline LiCu2O2. Earlier reported anomalies on
magnetization curves correspond to magnetic field values where we observe
changes of the NMR spectral shape. For the interpretation of the field and
temperature evolutions of our NMR spectra, the magnetic structures were
analyzed in the frame of the phenomenological theoretical approach of the
Dzyaloshinskii-Landau theory. A set of possible planar and collinear structures
was obtained. Most of these structures have an unusual configuration; they are
characterized by a two-component order parameter and their magnetic moments
vary harmonically not only in direction, but also in size. From the modeling of
the observed spectra, a possible scenario of magnetic structure transformations
is obtained.
