  This work provides the community with an easily executable open-source Python
package designed to automize the evaluation of Interfacial Phonons (InterPhon).
Its strategy of arbitrarily defining the interfacial region and periodicity
alleviates the excessive computational cost in applying ab initio phonon
calculations to interfaces and enables efficient extraction of interfacial
phonons. InterPhon makes it possible to apply all of the phonon-based
predictions that have been available for bulk systems, to interfacial systems.
The first example, in which this package was applied to InAs surfaces,
demonstrates a systematic structure search for unexplored surface
reconstructions, navigated by the imaginary mode of surface phonons. It
eventually explains the anisotropic surface vibrations of the polar crystal.
The second example, involving oxygen adsorption on Cu, reveals
adsorption-induced vibrational change and its contribution to energetic
stability. The third example, on a Si/GaAs interface, shows distinct
vibrational patterns depending on interfacial structures. It leads to a
prediction regarding the structural transition of interfaces and unveils the
processing conditions for spontaneous growth of GaAs nanowires on Si.
High-level automation in InterPhon will be of great help in elucidating
interfacial atomic dynamics and in implementing an automated computational
workflow for diverse interfacial systems.
