High precision numerical estimates of acoustic phonon frequencies of nonspherical nanoparticles
We introduce an adapted method for calculating the acoustic vibrational frequencies of arbitrarily shaped nanoparticles to high precision. Molecular dynamics simulation results are tested against exact solutions for a free sphere, a hollow sphere and a spheroid. This permits theoretical predictions of the frequencies of peaks in low frequency Raman spectra. Our results demonstrate that vibrational frequencies can be calculated for a wide range of low frequency modes with accuracies on the order of a tenth of a percent.