  The observational data on the large scale structure (LSS) of the Universe are
used to determine cosmological parameters within the class of adiabatic
inflationary models. We show that a mixed dark matter model with cosmological
constant ($\Lambda$MDM model) and parameters $\Omega_m=0.37^{+0.25}_{-0.15}$,
$\Omega_{\Lambda}=0.69^{+0.15}_{-0.20}$, $\Omega_{\nu}=0.03^{+0.07}_{-0.03}$,
$N_{\nu}=1$, $\Omega_b=0.037^{+0.033}_{-0.018}$, $n_s=1.02^{+0.09}_{-0.10}$,
$h=0.71^{+0.22}_{-0.19}$, $b_{cl}=2.4^{+0.7}_{-0.7}$ (1$\sigma$ confidence
limits) matches observational data on LSS, the nucleosynthesis constraint,
direct measurements of the Hubble constant, the high redshift supernova type Ia
results and the recent measurements of the location and amplitude of the first
acoustic peak in the CMB anisotropy power spectrum. The best model is $\Lambda$
dominated (65% of the total energy density) and has slightly positive
curvature, $\Omega=1.06$. The clustered matter consists in 8% massive
neutrinos, 10% baryons and 82% cold dark matter (CDM). It is shown that the LSS
observations together with the Boomerang (+MAXIMA-1) data on the first acoustic
peak rule out zero-$\Lambda$ models at more than $2\sigma$ confidence level.
