Returns an array giving the frequencies (squared) corresponding to the normal-mode
motions. First index indicates the wave vector, and second index indicates the
eigenvector. Length of second index is coordinateDim.
Set the fudge factor applied to frequencies. The squared-frequencies returned
by getOmegaSquared will be the nominal values divided by the given
fudge factor. Thus a smaller value of this fudge factor will make for "tighter"
harmonic springs, corresponding to to smaller deviation from the lattice sites.