Mass-density relationship in molecular cloud clumps
  We study the mass-density relationship n ~ m^x in molecular cloud
condensations (clumps), considering various equipartition relations between
their gravitational, kinetic, internal and magnetic energies. Clumps are
described statistically, with a density distribution that reflects a lognormal
probability density function (pdf) in turbulent cold interstellar medium. The
clump mass-density exponent $x$ derived at different scales $L$ varies in most
of the cases within the range $-2.5\lesssim x \lesssim-0.2$, with a pronounced
scale dependence and in consistency with observations. When derived from the
global size-mass relationship m ~ l^{\gamma_{glob}} for set of clumps,
generated at all scales, the clump mass-density exponent has typical values
$-3.0\lesssim x(\gamma_{glob}) \lesssim -0.3$ that depend on the forms of
energy, included in the equipartition relations and on the velocity scaling law
whereas the description of clump geometry is important when magnetic energy is
taken into account.
