diff -u pyoz-0.2.3/_features.txt pyoz-0.3/_features.txt
--- pyoz-0.2.3/_features.txt	2009-07-29 10:00:10.000000000 +0200
+++ pyoz-0.3/_features.txt	2009-08-12 14:09:09.000000000 +0200
@@ -1,14 +1,13 @@
 list of features of pyOZ
 ========================
 
-released:	29. July 2009
-version:	0.2.3
-
+released:	12. August 2009
+version:	0.3
 
     * general features
           o bulk calculations for simple atomic/ionic systems (no atomic details in molecules and molecular ions) on McMillan-Mayer level
           o simple iteration scheme (direct Picard iteration)
-          o (not available at the moment) improved iteration scheme (Newton-Raphson/conjugate gradients) for HNC closure
+          o improved iteration scheme (Newton-Raphson/conjugate gradients)
           o graphics output using Matplotlib
     * supported closure relations
           o Hypernetted Chain (HNC)
@@ -30,4 +29,3 @@
           o partial structure factors S(k)
           o pair potentials U(r)
           o total interaction potential - U(r) + indirect correlation function
-
diff -u pyoz-0.2.3/_notes.txt pyoz-0.3/_notes.txt
--- pyoz-0.2.3/_notes.txt	2009-07-29 10:00:21.000000000 +0200
+++ pyoz-0.3/_notes.txt	2009-08-12 14:40:09.000000000 +0200
@@ -1,9 +1,8 @@
 release notes for pyOZ
 ======================
 
-released:	29. July 2009
-version:	0.2.3
-... 
+released:	12. August 2009
+version:	0.3
 
 
 check the website http://pyoz.vrbka.net
@@ -13,24 +12,34 @@
     - theory
 
 
-changes from the previous release (0.2.2)
+changes from the previous release (0.2.3)
     - improved readability of the main code
     - bugfixes
     - output of partial structure factors S(k)
+    - newton-raphson/conjugate gradients algorithm reenabled
+
+!!! IMPORTANT !!!
+    the convergence of the NR/CG algorithm is heavily dependent on 
+    the quality of the involved operators and their adjoints
+    
+    particularly in the very beginning, when the linear approximation
+    to the problem is not very good, the algorithm frequently fails 
+    to converge and switches to the classical picard scheme
+!!! IMPORTANT !!!
 
 
 revisions/descriptions of individual source files
     - changed files denoted with star (*)
 
-pyoz.py ........................................... 0.1.7*
+pyoz.py ........................................... 0.1.8*
     main program
 pyoz_closure.py ................................... 0.1.1
     definition of closures
-pyoz_const.py ..................................... 0.1.6*
+pyoz_const.py ..................................... 0.1.6
     definition of constants
 pyoz_dft.py ....................................... 0.1.4
     definition of fourier transforms
-pyoz_input.py ..................................... 0.1.8*
+pyoz_input.py ..................................... 0.1.9*
     handling of input
 pyoz_misc.py ...................................... 0.1.3
     miscellanous routines
@@ -40,6 +49,6 @@
     definition and handling of pair potentials
 pyoz_property.py .................................. 0.1.5
     evaluation of thermodynamic properties
-pyoz_solver.py .................................... 0.1.2*
+pyoz_solver.py .................................... 0.1.2
     optimized solvers for special cases
 
diff -u pyoz-0.2.3/pyoz_const.py pyoz-0.3/pyoz_const.py
--- pyoz-0.2.3/pyoz_const.py	2009-07-29 10:03:35.000000000 +0200
+++ pyoz-0.3/pyoz_const.py	2009-08-12 14:12:38.000000000 +0200
@@ -15,7 +15,7 @@
 from math import sqrt, pi
 from scipy import inf
 
-pyoz_version = "0.2.3"
+pyoz_version = "0.3"
 
 class const:
   """
diff -u pyoz-0.2.3/pyoz_input.py pyoz-0.3/pyoz_input.py
--- pyoz-0.2.3/pyoz_input.py	2009-08-04 16:51:51.000000000 +0200
+++ pyoz-0.3/pyoz_input.py	2009-08-12 14:46:37.000000000 +0200
@@ -8,7 +8,7 @@
 
 """
 Module with functions for input file parsing
-revision of this file: 0.1.8
+revision of this file: 0.1.9
 """
 
 # import external modules
@@ -354,8 +354,8 @@
           raise badValue((i, "only positive dsqn values are allowed"))
       elif (match(r'use_nr$', keyword)):
         do_nr = True
-        print("NR/CG method has been disabled in this version due to severe problems!")
-        sys.exit(1)
+        #print("NR/CG method has been disabled in this version due to severe problems!")
+        #sys.exit(1)
       elif (match(r'nr_mix_param$', keyword)):
         nr_mix_param = float((l.split())[1])
         if ((nr_mix_param < 0) or (nr_mix_param > 1)):
@@ -438,6 +438,7 @@
   ctrl['nr_noconv_incr'] = nr_noconv_incr
   if (ctrl['do_nr']):
     print("\n\tNewton-Raphson iteration method will be used")
+    print("\tsupport of Newton-Raphson is highly experimental!")
     print("\tNR max iterations\t\t%lu" % ctrl['nr_max_iter'])
     print("\tNR initial mix parameter\t%e" % ctrl['nr_mix_param'])
     print("\tNR relative convergence factor\t%e" % ctrl['nr_convergence_factor'])
@@ -596,12 +597,6 @@
     sys.exit(1)
   # end if (closure_name in supported_closures)
 
-  # newton-raphson can be used only with the HNC closure!
-  if (ctrl['do_nr'] and syst['closure_name'] != 'hnc'):
-    #print("\tillegal combination of Newton-Raphson and closure (only HNC supported!)")
-    print("\tsupport of Newton-Raphson with PY closure is highly experimental!")
-    #sys.exit(1)
-
   # names of the constituents
   # if not given, use A, B, ...
   syst['name'] = name_value
diff -u pyoz-0.2.3/pyoz.py pyoz-0.3/pyoz.py
--- pyoz-0.2.3/pyoz.py	2009-07-28 15:24:12.000000000 +0200
+++ pyoz-0.3/pyoz.py	2009-08-12 13:56:16.000000000 +0200
@@ -9,7 +9,7 @@
 """
 Program for numerical solution of the Ornstein-Zernike equation
 version of the program is defined in pyoz_const.py
-revision of this file: 0.1.7
+revision of this file: 0.1.8
 
 check the file _features.txt and website http://pyoz.vrbka.net for further information
 
@@ -492,7 +492,14 @@
             # the operator works with the matrix CF, set according to the used closure
             for i in range(syst['ncomponents']):
               for j in range(syst['ncomponents']):
-                Rq[i,j] = dft.dfbt(Rcur[i,j])[0]
+                # even though R is r-space function, we are using the inverse FT here
+                # the definition of the adjoint requires its usage here!
+                # the problem is also the normalization sqrt(rho_i rho_j) that would be applied
+                # incorrectly in case normal FT would be used here
+                # note that the sinus transform is the same in r- and k-spaces => the difference really
+                # lies in the normalization
+                #Rq[i,j] = dft.dfbt(Rcur[i,j])[0]
+                Rq[i,j] = dft.idfbt(Rcur[i,j])
                 
             # matricial product
             for dr in range(ctrl['npoints']):
@@ -500,8 +507,15 @@
  
             for i in range(syst['ncomponents']):
               for j in range(syst['ncomponents']):
+                # even though SRS is k-space function, we are using the forward FT here
+                # the definition of the adjoint requires its usage here!
+                # the problem is also the normalization sqrt(rho_i rho_j) that would be applied
+                # incorrectly in case iFT would be used here
+                # note that the sinus transform is the same in r- and k-spaces => the difference really
+                # lies in the normalization
                 # remember that FT returns 2 functions in this case
-                SRSq[i,j] = dft.idfbt(SRS[i,j])
+                #SRSq[i,j] = dft.idfbt(SRS[i,j])
+                SRSq[i,j] = dft.dfbt(SRS[i,j])[0]
                 
             # not a matricial product!
             AtR = Rcur - SRSq*CF
Only in pyoz-0.3: tests