fixed same bug, yet in a different place.

examples/test_bh.c

@@ -353,9 +353,6 @@ void iact_pair ( struct cell *ci , struct cell *cj ) {
             for ( k = j+1 ; k < 8 ; k++ )
                 iact_pair( ci->progeny[j] , cj->progeny[k] );
             
-    /* Otherwise, compute interactions. */
-    else {
-    
     /* Get the minimum distance between both cells. */
     for ( r2 = 0.0, k = 0 ; k < 3 ; k++ ) {
         dx[k] = fabs( ci->loc[k] - cj->loc[k] );
@@ -365,7 +362,7 @@ void iact_pair ( struct cell *ci , struct cell *cj ) {
         }
 
     /* Sufficiently well-separated? */
-        if ( r2/ci->h[0] < dist_min*dist_min ) {
+    if ( r2/ci->h[0] > dist_min*dist_min ) {
 
         /* Compute the center of mass interactions. */
         iact_pair_pc( ci , cj );
@@ -373,6 +370,12 @@ void iact_pair ( struct cell *ci , struct cell *cj ) {
 
         }
 
+    /* Recurse? */
+    else if ( ci->split && cj->split )
+        for ( j = 0 ; j < 8 ; j++ )
+            for ( k = j+1 ; k < 8 ; k++ )
+                iact_pair( ci->progeny[j] , cj->progeny[k] );
+            
     /* Otherwise, do direct interactions. */
     else {
 
@@ -414,8 +417,6 @@ void iact_pair ( struct cell *ci , struct cell *cj ) {
 
         } /* otherwise, compute interactions directly. */
 
-        } /* otherwise, compute interactions. */
-
     }