diff --git a/README.md b/README.md
new file mode 100644
index 0000000..9f2692b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,74 @@
+# MuMassCalculator
+**A java library to Compute Compton, Raleigh, Photoelectric and Pair Production Cross sections**
+
+MuMassCalculator is derived from the NIST XCOM web application used to calculate
+photon cross sections for scattering, photoelectric absorption and pair production,
+as well as total attenuation coefficients, for any element, compound (Z ≤ 100),
+at energies from 1 keV to 100 GeV.
+
+**Acknowledgement:**
+
+XCOM: Photon Cross Sections DatabaseNIST Standard Reference Database 8 (XGAM),
+M.J. Berger, J.H. Hubbell, S.M. Seltzer, J. Chang, J.S. Coursey, R. Sukumar, D.S. Zucker, and K. Olsen,
+NIST, PML, Radiation Physics Division
+
+See  https://dx.doi.org/10.18434/T48G6X  for detailed information about XCOM
+
+Tabulated XCOM data is used with permission
+
+**Notes:**
+
+Unlike XCOM, MuMassCalculator does not support mixtures.
+
+MuMassCalculator was developed with JavaSE-1.8 (64-bit) and tested in the Eclipse IDE and as an ImageJ PlugIn with ImageJ 1.53i
+
+MuMassCalculator has no ImageJ dependencies.
+
+See: https://imagej.nih.gov/ij/
+
+**Download:**
+
+A MuMassCalculator jar file, JavaDocs and sample ImageJ PlugIn are available at
+
+https://drive.google.com/drive/folders/1fshrESwC7-sY6RYjsfVgYdudNeBxM_L-?usp=sharing
+
+MuMassCalc_J8Lib.jar contains the java source and class files.
+MuMassCalculatorDocs contains JavaDocs html files
+My_MuMassPlotPlugin2.java contains the source code for a sample ImageJ Plugin
+
+
+**Use:**
+
+**_ImageJ_**
+
+Put MuMassCalc_J8Lib.jar and MuMassCalculatorDocs to the ImageJ/plugins/jars folder.
+   
+Put My_MuMassPlotPlugin2.java example to the ImageJ/plugins folder.
+   
+Use ImageJ menu Plugins/Macros/Edit and browse to My_MuMassPlotPlugin2.java in the plugins folder.
+  
+In the plugin editor window Select File/ Compile and Run
+
+**_Eclipse_**	put MuMassCalc_J8Lib.jar to your eclipse-workspace folder and add it to your project's buildpath.
+
+An eclipse example class file
+
+
+import jhd.MuMassCalculator.*;
+
+	public class MuMassTest {
+
+	public static void main(String[] args) {
+		MuMassCalculator mmc = new MuMassCalculator();
+		
+		double[] result = mmc.getMevArray("CA:1:C:1:O:3", .001, .1);
+		
+		for(double mev : result)
+		{
+			System.out.println(mev);
+		}
+		
+		double mev = mmc.getAtomMuMass("AC", .1, "Totattn");
+		System.out.println(mev);
+	}
+