diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 1560278a..e79a9110 100755
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -8,6 +8,7 @@ ADD_LBPM_EXECUTABLE( lbpm_segmented_pp )
 ADD_LBPM_EXECUTABLE( lbpm_segmented_decomp )
 ADD_LBPM_EXECUTABLE( lbpm_disc_pp )
 ADD_LBPM_EXECUTABLE( lbpm_captube_pp )
+ADD_LBPM_EXECUTABLE( lbpm_squaretube_pp )
 ADD_LBPM_EXECUTABLE( lbpm_BlobAnalysis )
 ADD_LBPM_EXECUTABLE( TestBubble )
 ADD_LBPM_EXECUTABLE( BasicSimulator )
diff --git a/tests/lbpm_squaretube_pp.cpp b/tests/lbpm_squaretube_pp.cpp
new file mode 100644
index 00000000..6f2c72d4
--- /dev/null
+++ b/tests/lbpm_squaretube_pp.cpp
@@ -0,0 +1,218 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <iostream>
+#include <exception>
+#include <stdexcept>
+#include <fstream>
+
+#include "common/ScaLBL.h"
+#include "common/Communication.h"
+#include "common/TwoPhase.h"
+#include "common/MPI_Helpers.h"
+
+int main(int argc, char **argv)
+{
+	//*****************************************
+	// ***** MPI STUFF ****************
+	//*****************************************
+	// Initialize MPI
+	int rank,nprocs;
+	MPI_Init(&argc,&argv);
+    MPI_Comm comm = MPI_COMM_WORLD;
+	MPI_Comm_rank(comm,&rank);
+	MPI_Comm_size(comm,&nprocs);
+	// parallel domain size (# of sub-domains)
+	int nprocx,nprocy,nprocz;
+	int iproc,jproc,kproc;
+	int sendtag,recvtag;
+	//*****************************************
+	// MPI ranks for all 18 neighbors
+	//**********************************
+	int rank_x,rank_y,rank_z,rank_X,rank_Y,rank_Z;
+	int rank_xy,rank_XY,rank_xY,rank_Xy;
+	int rank_xz,rank_XZ,rank_xZ,rank_Xz;
+	int rank_yz,rank_YZ,rank_yZ,rank_Yz;
+	//**********************************
+	MPI_Request req1[18],req2[18];
+	MPI_Status stat1[18],stat2[18];
+
+	double TubeWidth =15.0;
+	int BC;
+	int BubbleTop,BubbleBottom;
+	TubeWidth=strtod(argv[1],NULL);
+	BC=atoi(argv[2]);
+	BubbleBottom = atoi(argv[3]);
+	BubbleTop = atoi(argv[4]);
+
+	if (rank == 0){
+		printf("********************************************************\n");
+		printf("Generate 3D capillary tube geometry with side = %f voxels \n",TubeWidth);
+		printf("********************************************************\n");
+	}
+
+	// Variables that specify the computational domain  
+	string FILENAME;
+	int Nx,Ny,Nz;		// local sub-domain size
+	int nspheres;		// number of spheres in the packing
+	double Lx,Ly,Lz;	// Domain length
+	int i,j,k,n;
+
+	// pmmc threshold values
+
+	if (rank==0){
+		//.......................................................................
+		// Reading the domain information file
+		//.......................................................................
+		ifstream domain("Domain.in");
+		domain >> nprocx;
+		domain >> nprocy;
+		domain >> nprocz;
+		domain >> Nx;
+		domain >> Ny;
+		domain >> Nz;
+		domain >> nspheres;
+		domain >> Lx;
+		domain >> Ly;
+		domain >> Lz;
+		//.......................................................................
+	}
+	// **************************************************************
+	// Broadcast simulation parameters from rank 0 to all other procs
+	MPI_Barrier(comm);
+	// Computational domain
+	MPI_Bcast(&Nx,1,MPI_INT,0,comm);
+	MPI_Bcast(&Ny,1,MPI_INT,0,comm);
+	MPI_Bcast(&Nz,1,MPI_INT,0,comm);
+	MPI_Bcast(&nprocx,1,MPI_INT,0,comm);
+	MPI_Bcast(&nprocy,1,MPI_INT,0,comm);
+	MPI_Bcast(&nprocz,1,MPI_INT,0,comm);
+	MPI_Bcast(&nspheres,1,MPI_INT,0,comm);
+	MPI_Bcast(&Lx,1,MPI_DOUBLE,0,comm);
+	MPI_Bcast(&Ly,1,MPI_DOUBLE,0,comm);
+	MPI_Bcast(&Lz,1,MPI_DOUBLE,0,comm);
+	//.................................................
+	MPI_Barrier(comm);
+	
+	// **************************************************************
+	if (nprocs != nprocx*nprocy*nprocz){
+		printf("nprocx =  %i \n",nprocx);
+		printf("nprocy =  %i \n",nprocy);
+		printf("nprocz =  %i \n",nprocz);
+		INSIST(nprocs == nprocx*nprocy*nprocz,"Fatal error in processor count!");
+	}
+
+	if (rank==0){
+		printf("********************************************************\n");
+		printf("Sub-domain size = %i x %i x %i\n",Nz,Nz,Nz);
+		printf("Parallel domain size = %i x %i x %i\n",nprocx,nprocy,nprocz);
+		printf("********************************************************\n");
+	}
+
+	// Initialized domain and averaging framework for Two-Phase Flow
+	Domain Dm(Nx,Ny,Nz,rank,nprocx,nprocy,nprocz,Lx,Ly,Lz,BC);
+	Dm.CommInit(comm);
+	TwoPhase Averages(Dm);
+
+	InitializeRanks( rank, nprocx, nprocy, nprocz, iproc, jproc, kproc,
+			 	 	 rank_x, rank_y, rank_z, rank_X, rank_Y, rank_Z,
+			 	 	 rank_xy, rank_XY, rank_xY, rank_Xy, rank_xz, rank_XZ, rank_xZ, rank_Xz,
+			 	 	 rank_yz, rank_YZ, rank_yZ, rank_Yz );
+	 
+	MPI_Barrier(comm);
+
+	Nz += 2;
+	Nx = Ny = Nz;	// Cubic domain
+
+	int N = Nx*Ny*Nz;
+	int dist_mem_size = N*sizeof(double);
+
+	//.......................................................................
+	// Filenames used
+	char LocalRankString[8];
+	char LocalRankFilename[40];
+	char LocalRestartFile[40];
+	char tmpstr[10];
+	sprintf(LocalRankString,"%05d",rank);
+	sprintf(LocalRankFilename,"%s%s","ID.",LocalRankString);
+	sprintf(LocalRestartFile,"%s%s","Restart.",LocalRankString);
+	
+//	printf("Local File Name =  %s \n",LocalRankFilename);
+	// .......... READ THE INPUT FILE .......................................
+//	char value;
+	char *id;
+	id = new char[N];
+	int sum = 0;
+	double sum_local;
+	double iVol_global = 1.0/(1.0*(Nx-2)*(Ny-2)*(Nz-2)*nprocs);
+	//if (pBC) iVol_global = 1.0/(1.0*(Nx-2)*nprocx*(Ny-2)*nprocy*((Nz-2)*nprocz-6));
+	double porosity, pore_vol;
+
+	sum=0;
+	for (k=0;k<Nz;k++){
+		for (j=0;j<Ny;j++){
+			for (i=0;i<Nx;i++){
+				n = k*Nx*Ny + j*Nz + i;
+				// square capillary tube aligned with the z direction
+				Averages.SDs(i,j,k) = 0.5*Nx+TubeWidth-i;
+				Averages.SDs(i,j,k) = min(Averages.SDs(i,j,k),0.5*Nx-TubeWidth+i);
+				Averages.SDs(i,j,k) = min(Averages.SDs(i,j,k),0.5*Ny-TubeWidth-j);
+				Averages.SDs(i,j,k) = min(Averages.SDs(i,j,k),0.5*Ny-TubeWidth+j);
+				Averages.SDs(i,j,k) = min(Averages.SDs(i,j,k),0.5*Nz-TubeWidth-k);
+				Averages.SDs(i,j,k) = min(Averages.SDs(i,j,k),0.5*Nz-TubeWidth+k);
+
+				// Initialize phase positions
+				if (Averages.SDs(i,j,k) < 0.0){
+					id[n] = 0;
+				}
+				else if (Dm.kproc*Nz+k<BubbleBottom){
+					id[n] = 2;
+					sum++;
+				}
+				else if (Dm.kproc*Nz+k<BubbleTop){
+					id[n] = 1;
+					sum++;
+				}
+				else{
+					id[n] = 2;
+					sum++;
+				}
+			}
+		}
+	}
+	porosity = double(sum)/double(1.0*N);
+	// Compute the pore volume
+	sum_local = 0.0;
+	for ( k=1;k<Nz-1;k++){
+		for ( j=1;j<Ny-1;j++){
+			for ( i=1;i<Nx-1;i++){
+				n = k*Nx*Ny+j*Nx+i;
+				if (id[n] > 0){
+					sum_local += 1.0;
+				}
+			}
+		}
+	}
+	MPI_Allreduce(&sum_local,&pore_vol,1,MPI_DOUBLE,MPI_SUM,comm);
+
+	//.........................................................
+	// don't perform computations at the eight corners
+	id[0] = id[Nx-1] = id[(Ny-1)*Nx] = id[(Ny-1)*Nx + Nx-1] = 0;
+	id[(Nz-1)*Nx*Ny] = id[(Nz-1)*Nx*Ny+Nx-1] = id[(Nz-1)*Nx*Ny+(Ny-1)*Nx] = id[(Nz-1)*Nx*Ny+(Ny-1)*Nx + Nx-1] = 0;
+	//.........................................................
+
+    sprintf(LocalRankFilename,"SignDist.%05i",rank);
+    FILE *DIST = fopen(LocalRankFilename,"wb");
+    fwrite(Averages.SDs.get(),8,Averages.SDs.length(),DIST);
+    fclose(DIST);
+
+	sprintf(LocalRankFilename,"ID.%05i",rank);
+	FILE *ID = fopen(LocalRankFilename,"wb");
+	fwrite(id,1,N,ID);
+	fclose(ID);
+
+	// ****************************************************
+	MPI_Barrier(comm);
+	MPI_Finalize();
+	// ****************************************************
+}