diff --git a/cube.py b/cube.py
index 85dccad..9c0f846 100644
--- a/cube.py
+++ b/cube.py
@@ -2,18 +2,18 @@ from math import *
 
 ## Exp W. Modes of long cyclinder (1D) ##
 u = 343 #speed of sound
-a = 0.2 #length of tube
+a = 0.2 #length width and height of cube
 b = 0.2
 c = 0.2
-fqn = [] #frequencies
-f = []
+fqn = [] #frequencies and respective quantum numbers
+f = [] # frequencies
 
 for l in range (0,4):
     for m in range (0,4):
         for n in range (0,4):
             qn = [l,m,n]
             frequency = (u/2)*(sqrt((l/a)**2+(m/b)**2+(n/c)**2))
-            if frequency in f:
+            if frequency in f: # check for duplicatesq
                 continue
             else:
                 f.append(frequency)