diff --git a/src/opt/mpi/include/rop_types.cc.h b/src/opt/mpi/include/rop_types.cc.h
index 813a062..3046c7f 100644
--- a/src/opt/mpi/include/rop_types.cc.h
+++ b/src/opt/mpi/include/rop_types.cc.h
@@ -14,24 +14,20 @@ namespace CNORXZ
 	template <class PosT>
 	constexpr decltype(auto) CROpRoot<T,IndexT>::operator()(const PosT& pos) const
 	{
-	    const SizeT L = mIndex->lmax().val();
-	    const SizeT m = mIndex->myrank();
-	    const SizeT dst = ( m + pos.val() ) % L;
-	    const SizeT src = ( m - pos.val() + L ) % L;
-	    
+	    return (mData+mPos[pos.val()])[pos.next().val()];
 	}
 
 	template <typename T, class IndexT>
 	constexpr decltype(auto) CROpRoot<T,IndexT>::operator()() const
 	{
-
+	    return (mData+mPos[0])[0];
 	}
 
 	template <typename T, class IndexT>
 	template <SizeT I>
 	constexpr decltype(auto) CROpRoot<T,IndexT>::rootSteps(const IndexId<I>& id) const
 	{
-
+	    
 	}
     
 	/*===============+
diff --git a/src/opt/mpi/include/rop_types.h b/src/opt/mpi/include/rop_types.h
index 814e0fd..3f88843 100644
--- a/src/opt/mpi/include/rop_types.h
+++ b/src/opt/mpi/include/rop_types.h
@@ -20,7 +20,7 @@ namespace CNORXZ
 	class CROpRoot : public COpInterface<CROpRoot<T,IndexT>>
 	{
 	public:
-	    typedef COpInterface<CROpRoot<T,IndexT>> OI;
+	    typedef COpInterface<CROpRoot<T,IndexT >> OI;
 
 	    constexpr CROpRoot() = default;
 
@@ -33,8 +33,11 @@ namespace CNORXZ
 	    constexpr decltype(auto) rootSteps(const IndexId<I>& id) const;
 
 	private:
-	    const T* mData;
-	    COpRoot
+	    // 
+	    const T* mData; // must include all needed data, also that of other ranks (to be transmitted before!)
+	    // maps the global (!) position to mData!!
+	    const SizeT* mPos; // position map (needed to indicate position to data transmitted from other ranks)
+	    Sptr<IndexT> mIndex;
 	};
 
 	template <typename T, class IndexT>