  Two-dimensional (2D) layered materials have been extensively studied owing to
their fascinating and technologically relevant properties. Their
functionalities can be often tailored by the interlayer stacking pattern.
Low-frequency (LF) Raman spectroscopy provides a quick, non-destructive and
inexpensive optical technique for stacking characterization, since the
intensities of LF interlayer vibrational modes are sensitive to the details of
the stacking. A simple and generalized interlayer bond polarizability model is
proposed here to explain and predict how the LF Raman intensities depend on
complex stacking sequences for any thickness in a broad array of 2D materials,
including graphene, MoS2, MoSe2, NbSe2, Bi2Se3, GaSe, h-BN, etc. Additionally,
a general strategy is proposed to unify the stacking nomenclature for these 2D
materials. Our model reveals the fundamental mechanism of LF Raman response to
the stacking, and provides general rules for stacking identification.
