  Using an atomistic model that simultaneously treats the dynamics of
translational and spin degrees of freedom, we perform combined molecular and
spin dynamics simulations to investigate the mutual influence of the phonons
and magnons on their respective frequency spectra and lifetimes in
ferromagnetic bcc iron. By calculating the Fourier transforms of the space- and
time-displaced correlation functions, the characteristic frequencies and the
linewidths of the vibrational and magnetic excitation modes were determined.
Comparison of the results with that of the stand-alone molecular dynamics and
spin dynamics simulations reveals that the dynamic interplay between the
phonons and magnons leads to a shift in the respective frequency spectra and a
decrease in the lifetimes. Moreover, in the presence of lattice vibrations,
additional longitudinal magnetic excitations were observed with the same
frequencies as the longitudinal phonons.
