bugfix for 2 recenty reported neighbor issues, also a ReaxFF fix species issue

src/npair_full_bin.cpp

@@ -80,7 +80,7 @@ void NPairFullBin::build(NeighList *list)
     // loop over all atoms in surrounding bins in stencil including self
     // skip i = j
 
-    ibin = coord2bin(x[i]);
+    ibin = atom2bin[i];
 
     for (k = 0; k < nstencil; k++) {
       for (j = binhead[ibin+stencil[k]]; j >= 0; j = bins[j]) {