Use a Krause-style iteration

src/one-body-sample.parset

@@ -28,7 +28,7 @@ nu = 0.3 # Needs to be strictly below 0.5; the closer we get, the
 tolerance = 1e-11
 
 [solver.tnnmg]
-maxiterations = 1000000
+maxiterations = 1 # Krause modification; old: 1000000
 fixed_point_iterations = 1000000
 fixed_point_tolerance = 1e-11
 
@@ -46,8 +46,8 @@ nu2 = 1
 # A vvv- or vvvv-cycle appears to be even faster.
 # And leaving off the postsmoothing is even better yet
 nu1 = 1
-mu = 4 # Note: the more steps we make here, the fewer FPI we need
-nu2 = 1
+mu = 1 # Krause modification; old: 4
+nu2 = 0 # Krause modification; old: 1
 
 [localsolver]
 # Observation: Increasing this value yields noticeable additional