quantum-espresso/test-suite/epw_tdbe/ph.in

--
&inputph
  prefix   = 'si',
  epsil    = .true.,
  fildyn   = 'si.dyn',
  ldisp    = .true.
  fildvscf = 'dvscf'
  nq1=3,
  nq2=3,
  nq3=3,
  tr2_ph   =  1.0d-14,
 /