Fixing compile errors without MPI

models/PoissonSolver.cpp

@@ -522,8 +522,8 @@ void ScaLBL_Poisson::Run(double *ChargeDensity, int timestep_from_Study){
     
 	//.......create and start timer............
 	//double starttime,stoptime,cputime;
-	//ScaLBL_Comm->Barrier(); comm.barrier();
-	//starttime = MPI_Wtime();
+	//comm.barrier();
+    //auto t1 = std::chrono::system_clock::now();
 
 	timestep=0;
 	double error = 1.0;
@@ -579,11 +579,11 @@ void ScaLBL_Poisson::Run(double *ChargeDensity, int timestep_from_Study){
     }
 
 	//************************************************************************/
-	//stoptime = MPI_Wtime();
 	////if (rank==0) printf("LB-Poission Solver: a steady-state solution is obtained\n");
 	////if (rank==0) printf("---------------------------------------------------------------------------\n");
 	//// Compute the walltime per timestep
-	//cputime = (stoptime - starttime)/timestep;
+	//auto t2 = std::chrono::system_clock::now();
+	//double cputime = std::chrono::duration<double>( t2 - t1 ).count() / timestep;
 	//// Performance obtained from each node
 	//double MLUPS = double(Np)/cputime/1000000;