**Figure 2**
The number of PDB entries (in thousands) as a function of various parameters. The blue histogram in (*b*), (*c*) and (*d*) is for the minimum eigenvalue and the red histogram is for the maximum eigenvalue. The leftmost and rightmost bins include all cases with values less than or greater than the limits given on the axis, respectively. The eigenvalues are given in rad^{2} for **L** and in Å^{2} for **T**. The total number of TLS groups is 203 261 for (*a*), (*b*) and (*c*) and about 70 000 for (*d*) when the matrix **V** could be calculated. (*a*) The number of TLS groups per entry; the largest is 283. (*b*) Distribution of eigenvalues of the matrix **L**; the minimum eigenvalue varies from −0.285 to 0.164 and the maximum eigenvalue varies from −0.001 to 0.409. (*c*) Distribution of eigenvalues of the matrix **T**; the minimum eigenvalue varies from −20.716 to 6.852 and the maximum eigenvalue varies from −1.551 to 28.676. (*d*) Distribution of eigenvalues of the matrix **V** (the **S** matrix optimized as described in the article); the minimum eigenvalue varies from −0.001 to 2.815 and the maximum eigenvalue varies from 0 to 5.950. |