  We present results of theoretical description and numerical calculation of
the dynamics of molecular liquids based on the Reference Interaction Site Model
/ Mode-Coupling Theory. They include the temperature-pressure(density)
dependence of the translational diffusion coefficients and orientational
relaxation times for acetonitrile and methanol in water at infinite dilution.
Anomalous behavior, i.e. the increase in mobility with density, is observed for
the orientational relaxation time of methanol, while acetonitrile does not show
any deviations from the usual. This effect is in qualitative agreement with the
recent data of MD simulation and with experimental measurements, which tells us
that presented theory is a good candidate to explain such kind of anomalies
from the microscopical point of view and with the connection to the structure
of the molecules.
