diff --git a/birefringence-waveform/waveform.py b/birefringence-waveform/waveform.py
index 4cd1a86977004b3636d550493899b3b018ae5f2b..41ec79b79c4fbb9fc8dd995beaea857fed10f6c8 100644
--- a/birefringence-waveform/waveform.py
+++ b/birefringence-waveform/waveform.py
@@ -3,17 +3,15 @@ import numpy as np
 import pycbc.conversions
 import lal
 
-def IMRPhenomParity(parity_lambdatilt, **kwds):
+def IMRPhenomParity(parity_Amu, **kwds):
 
     if 'approximant' in kwds:
         kwds.pop("approximant")
     hp, hc = get_fd_waveform(approximant="IMRPhenomXPHM", **kwds)
 
-    tempVal =  lal.H_SI * lal.PI * lal.PI * r / parity_lambdatilt;
+    temp =  parity_Amu * 1e9 * lal.QE_SI * lal.PI * lal.PI / lal.H0_SI
 
-    deltaPhi1 = tempVal * f * f;
+    hp_parity = hp + hc * temp * hp.sample_frequencies **2
+    hc_parity = hc - hp * temp * hp.sample_frequencies **2    
 
-    hp_parity = hp + hc * deltaPhi1;
-    hc_parity = hc - hp * deltaPhi1;
-
-    return hpd,hcd
+    return hp_parity, hc_parity