  We report on structure, vibrational properties and
weak-antilocalization-(WAL-) induced quantum correction to magnetoconductivity
in single crystal Bi2GeTe4. Surface band structure calculations show a single
Dirac cone corresponding to topological surface states in Bi2GeTe4. An
estimated phase coherence length, l_{\phi} ~ 143 nm and prefactor {\alpha} ~ -
1.54 from Hikami-Larkin-Nagaoka fitting of magnetoconductivity describe the
quantum correction to conductivity. An anomalous temperature dependence of A1g
Raman modes confirms enhanced electron-phonon interactions. Our results
establish the involvement of vibrations of Bi-Te with existence of topological
surface states and WAL in Bi2GeTe4.
