Index: hs_operators.py
===================================================================
--- hs_operators.py	(revision 7489)
+++ hs_operators.py	(working copy)
@@ -26,7 +26,8 @@
     async = True
     hermitian = True
 
-    def __init__(self, bd, gd, ksl, nblocks=None, async=None, hermitian=None):
+    def __init__(self, bd, gd, ksl, dtype, 
+                 nblocks=None, async=None, hermitian=None):
         """The constructor now calculates the work array sizes, but does not
         allocate them. Here is a summary of the relevant variables and the
         cases handled.
@@ -61,6 +62,7 @@
         """
         self.bd = bd
         self.gd = gd
+        self.dtype = dtype
         self.work1_xG = None
         self.work2_xG = None
         self.A_qnn = None
@@ -81,6 +83,18 @@
         mynbands = self.bd.mynbands
         nbands = self.bd.nbands
         G = self.gd.n_c.prod()
+
+        # Handle nblocks specified as a literal to mean MB.
+        # Converts to closest value of integer nblocks.
+        # if isinstance (self.nblocks,str):
+        #     sizeof_single_wfs = self.gd.bytecount(self.dtype)
+        #     number_wfs = float(self.nblocks)*1024*1024/sizeof_single_wfs
+        #     temp_nblocks = int(np.floor(mynbands/multiple_wfs))
+        #     while (mynbands % temp_nblocks) != 0:
+        #         temp_nblocks -= temp_nblocks
+        #     assert temp_nblocks > 0
+        #     self.nblocks = temp_nblocks
+
         if ngroups == 1 and self.nblocks == 1:
             pass
         else:
@@ -115,7 +129,7 @@
         gdbytes = self.gd.bytecount(dtype)
         count = self.Q * mynbands**2
 
-        # Code semipasted from allocate_work_arrays
+        # Code semipasted from allocate_work_arrays        
         if ngroups == 1 and self.nblocks == 1:
             mem.subnode('work1_xG', mynbands * gdbytes)
         else: