diff --git a/src/utils/infrared.F90 b/src/utils/infrared.F90
index e8883fa3ffc10cd632609959a0c60fbc93bf6fe1..8bd1ca68f32a3ee7cc4e6f476434f9dc207ea6ae 100644
--- a/src/utils/infrared.F90
+++ b/src/utils/infrared.F90
@@ -33,7 +33,7 @@ program infrared
   implicit none
 
   integer :: iunit, ierr, ii, jj, iter, read_iter, max_iter, ini_iter, end_iter
-  FLOAT :: start_time, end_time
+  FLOAT :: start_time, end_time, mu
   FLOAT, allocatable :: time(:), dipole(:,:)
   CMPLX, allocatable :: ftdipole(:,:)
   type(space_t)     :: space
@@ -59,6 +59,7 @@ program infrared
 
   !These variables are documented in src/td/spectrum.F90
   call parse_variable(global_namespace, 'TDMaxSteps', 1500, max_iter)
+  call parse_variable(global_namespace, 'TDIonicTimeScale', CNST(1.0), mu)
   call parse_variable(global_namespace, 'PropagationSpectrumStartTime',  M_ZERO, start_time, units_inp%time)
   call parse_variable(global_namespace, 'PropagationSpectrumEndTime',  -M_ONE, end_time, units_inp%time)
   call parse_variable(global_namespace, 'PropagationSpectrumMaxEnergy', &
@@ -72,7 +73,7 @@ program infrared
 
   SAFE_ALLOCATE(dipole(0:max_iter+1, 1:3))
 
-  call read_dipole(dipole)
+  call read_dipole(dipole, mu)
 
   SAFE_ALLOCATE(ftdipole(1:max_freq, 1:3))
 
@@ -113,9 +114,9 @@ program infrared
 
 contains
 
-  subroutine read_dipole(dipole)
+  subroutine read_dipole(dipole, mu)
     FLOAT,   intent(out)   :: dipole(0:, :)
-
+    FLOAT,   intent(in)    :: mu
     FLOAT :: charge
 
     PUSH_SUB(read_dipole)
@@ -135,7 +136,7 @@ contains
       read(unit = iunit, iostat = ierr, fmt = *) read_iter, time(iter), &
         charge, dipole(iter, 1), dipole(iter, 2), dipole(iter, 3)
 
-      time(iter) =  units_to_atomic(units_out%time, time(iter))
+      time(iter) =  units_to_atomic(units_out%time, time(iter))*mu
 
       !dipole moment has unit of charge*length, charge has the same unit in both systems
       do ii = 1, 3