diff --git a/FDTD/engine.cpp b/FDTD/engine.cpp
index 691cfdd..21c6c3a 100644
--- a/FDTD/engine.cpp
+++ b/FDTD/engine.cpp
@@ -118,7 +118,7 @@ void Engine::ApplyVoltageExcite()
 		exc_pos = (int)numTS - (int)Op->E_Exc_delay[n];
 		exc_pos *= (exc_pos>0 && exc_pos<=(int)Op->ExciteLength);
 //			if (n==0) cerr << numTS << " => " << Op->ExciteSignal[exc_pos] << endl;
-		volt[Op->E_Exc_dir[n]][Op->E_Exc_index[0][n]][Op->E_Exc_index[1][n]][Op->E_Exc_index[2][n]] += Op->E_Exc_amp[n]*Op->ExciteSignal_volt[exc_pos];
+		GetVolt(Op->E_Exc_dir[n],Op->E_Exc_index[0][n],Op->E_Exc_index[1][n],Op->E_Exc_index[2][n]) += Op->E_Exc_amp[n]*Op->ExciteSignal_volt[exc_pos];
 	}
 
 	// write the first excitation into the file "et1"
@@ -164,7 +164,7 @@ void Engine::ApplyCurrentExcite()
 		exc_pos = (int)numTS - (int)Op->Curr_Exc_delay[n];
 		exc_pos *= (exc_pos>0 && exc_pos<=(int)Op->ExciteLength);
 //			if (n==0) cerr << numTS << " => " << Op->ExciteSignal[exc_pos] << endl;
-		curr[Op->Curr_Exc_dir[n]][Op->Curr_Exc_index[0][n]][Op->Curr_Exc_index[1][n]][Op->Curr_Exc_index[2][n]] += Op->Curr_Exc_amp[n]*Op->ExciteSignal_curr[exc_pos];
+		GetCurr(Op->Curr_Exc_dir[n],Op->Curr_Exc_index[0][n],Op->Curr_Exc_index[1][n],Op->Curr_Exc_index[2][n]) += Op->Curr_Exc_amp[n]*Op->ExciteSignal_curr[exc_pos];
 	}
 }
 
diff --git a/FDTD/engine.h b/FDTD/engine.h
index 7ef5123..db1c6f7 100644
--- a/FDTD/engine.h
+++ b/FDTD/engine.h
@@ -37,11 +37,11 @@ public:
 
 	virtual unsigned int GetNumberOfTimesteps() {return numTS;};
 
-	inline virtual FDTD_FLOAT GetVolt( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return volt[n][x][y][z]; }
-	inline virtual FDTD_FLOAT GetCurr( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return curr[n][x][y][z]; }
+	inline virtual FDTD_FLOAT& GetVolt( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return volt[n][x][y][z]; }
+	inline virtual FDTD_FLOAT& GetCurr( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return curr[n][x][y][z]; }
 
-	inline virtual FDTD_FLOAT& GetVolt( unsigned int n, unsigned int pos[] ) { return volt[n][pos[0]][pos[1]][pos[2]]; }
-	inline virtual FDTD_FLOAT& GetCurr( unsigned int n, unsigned int pos[] ) { return curr[n][pos[0]][pos[1]][pos[2]]; }
+	inline virtual FDTD_FLOAT& GetVolt( unsigned int n, unsigned int pos[] ) { return GetVolt(n,pos[0],pos[1],pos[2]); }
+	inline virtual FDTD_FLOAT& GetCurr( unsigned int n, unsigned int pos[] ) { return GetCurr(n,pos[0],pos[1],pos[2]); }
 
 protected:
 	Engine(const Operator* op);
diff --git a/FDTD/engine_sse.cpp b/FDTD/engine_sse.cpp
index 1859248..737c97b 100644
--- a/FDTD/engine_sse.cpp
+++ b/FDTD/engine_sse.cpp
@@ -69,7 +69,7 @@ void Engine_sse::UpdateVoltages()
 		for (pos[1]=0;pos[1]<numLines[1];++pos[1])
 		{
 			shift[1]=pos[1];
-			for (pos[2]=0;pos[2]<numLines[2]/4;++pos[2])
+			for (pos[2]=0;pos[2]<ceil(numLines[2]/4);++pos[2])
 			{
 				// x-polarization
 				temp.f[0] = curr_[1][pos[0]][pos[1]][pos[2]-(bool)pos[2]].f[3];
@@ -95,20 +95,6 @@ void Engine_sse::UpdateVoltages()
 	}
 }
 
-void Engine_sse::ApplyVoltageExcite()
-{
-	int exc_pos;
-	unsigned int pos;
-	//soft voltage excitation here (E-field excite)
-	for (unsigned int n=0;n<Op->E_Exc_Count;++n)
-	{
-		exc_pos = (int)numTS - (int)Op->E_Exc_delay[n];
-		exc_pos *= (exc_pos>0 && exc_pos<=(int)Op->ExciteLength);
-		pos = Op->E_Exc_index[2][n];
-		volt_[Op->E_Exc_dir[n]][Op->E_Exc_index[0][n]][Op->E_Exc_index[1][n]][pos/4].f[pos%4] += Op->E_Exc_amp[n]*Op->ExciteSignal[exc_pos];
-	}
-}
-
 void Engine_sse::UpdateCurrents()
 {
 	unsigned int pos[5];
@@ -118,7 +104,7 @@ void Engine_sse::UpdateCurrents()
 	{
 		for (pos[1]=0;pos[1]<numLines[1]-1;++pos[1])
 		{
-			for (pos[2]=0;pos[2]<numLines[2]/4;++pos[2]) // FIXME is this correct?
+			for (pos[2]=0;pos[2]<ceil(numLines[2]/4);++pos[2]) // FIXME is this correct?
 			{
 				// x-pol
 				temp.f[0] = volt_[1][pos[0]][pos[1]][pos[2]].f[1];
@@ -143,20 +129,3 @@ void Engine_sse::UpdateCurrents()
 		}
 	}
 }
-
-void Engine_sse::ApplyCurrentExcite()
-{
-}
-
-bool Engine_sse::IterateTS(unsigned int iterTS)
-{
-	for (unsigned int iter=0;iter<iterTS;++iter)
-	{
-		UpdateVoltages();
-		ApplyVoltageExcite();
-		UpdateCurrents();
-		ApplyCurrentExcite();
-		++numTS;
-	}
-	return true;
-}
diff --git a/FDTD/engine_sse.h b/FDTD/engine_sse.h
index 5141379..b980965 100644
--- a/FDTD/engine_sse.h
+++ b/FDTD/engine_sse.h
@@ -30,28 +30,20 @@ public:
 	virtual void Init();
 	virtual void Reset();
 
-	//!Iterate a number of timesteps
-	virtual bool IterateTS(unsigned int iterTS);
-
 	virtual unsigned int GetNumberOfTimesteps() {return numTS;};
 
-	inline virtual FDTD_FLOAT GetVolt( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return volt_[n][x][y][z/4].f[z%4]; }
-	inline virtual FDTD_FLOAT GetCurr( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return curr_[n][x][y][z/4].f[z%4]; }
+	inline virtual FDTD_FLOAT& GetVolt( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return volt_[n][x][y][z/4].f[z%4]; }
+	inline virtual FDTD_FLOAT& GetCurr( unsigned int n, unsigned int x, unsigned int y, unsigned int z ) const { return curr_[n][x][y][z/4].f[z%4]; }
 
 protected:
 	Engine_sse(const Operator_sse* op);
 	const Operator_sse* Op;
 
 	virtual void UpdateVoltages();
-	virtual void ApplyVoltageExcite();
 	virtual void UpdateCurrents();
-	virtual void ApplyCurrentExcite();
-
-	unsigned int numLines[3];
 
 	f4vector**** volt_;
 	f4vector**** curr_;
-	unsigned int numTS;
 };
 
 #endif // ENGINE_SSE_H
diff --git a/tools/array_ops.cpp b/tools/array_ops.cpp
index 6764c5e..b326e01 100644
--- a/tools/array_ops.cpp
+++ b/tools/array_ops.cpp
@@ -149,10 +149,7 @@ void Delete_N_3DArray_v4sf(f4vector**** array, const unsigned int* numLines)
 
 f4vector*** Create3DArray_v4sf(const unsigned int* numLines)
 {
-	if ((numLines[2] % 4) != 0) {
-		cerr << "sse engine needs number of mesh lines divideable by 4" << endl;
-		exit(1);
-	}
+	unsigned int numZ = ceil(numLines[2]/4)+1;
 
 	f4vector*** array=NULL;
 	unsigned int pos[3];
@@ -162,8 +159,8 @@ f4vector*** Create3DArray_v4sf(const unsigned int* numLines)
 		array[pos[0]] = new f4vector*[numLines[1]];
 		for (pos[1]=0;pos[1]<numLines[1];++pos[1])
 		{
-			array[pos[0]][pos[1]] = new f4vector[numLines[2]/4];
-			for (pos[2]=0;pos[2]<numLines[2]/4;++pos[2])
+			array[pos[0]][pos[1]] = new f4vector[numZ];
+			for (pos[2]=0;pos[2]<numZ;++pos[2])
 			{
 				array[pos[0]][pos[1]][pos[2]].f[0] = 0;
 				array[pos[0]][pos[1]][pos[2]].f[1] = 0;