  We explore the capabilities of the frequency-resolved frozen phonon
multislice method introduced in Phys. Rev. Lett. 124, 025501 (2020) to model
inelastic vibrational scattering in transmission electron microscopy. We review
the method in detail and discuss advantages of using a so called hotspot
thermostat instead of the $\delta$-thermostat used in our first report. We
apply the method to simulate vibrational electron energy loss spectra of
hexagonal boron nitride under plane wave illumination. Simulated spectroscopic
information well represents the theoretical phonon bandstructure of the studied
material, both in terms of energies as well as polarization vectors of
individual phonon modes.
