Using the correlative method of unsymmetrized self-consistent field we study equilibrium atomic properties of anharmonic crystals. Here we calculate dynamical characteristics of a weakly anharmonic crystal with the body-centered cubic lattice, namely, the quadratic correlation moments between atomic displacements and the mean square relative atomic displacements. Taking into account the nearest neighbour interactions in this lattice, the second order of the method enables one to calculate the correlations between the nearest, second, third and fifth neighbours. An influence of more distant interactions is discussed. Results are also correlated with those calculated early for the simple and face-centered cubic lattices.