Added Slab class for the slabs that are used to produce Tiles.

Signed-off-by: Jay Jay Billings <billingsjj@ornl.gov>

src/org.eclipse.ice.reflectivity/src/org/eclipse/ice/reflectivity/Slab.java

@@ -0,0 +1,28 @@
+/*******************************************************************************
+ * Copyright (c) 2013, 2014 UT-Battelle, LLC.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Initial API and implementation and/or initial documentation - 
+ *   Jay Jay Billings
+ *******************************************************************************/
+package org.eclipse.ice.reflectivity;
+
+/**
+ * Slabs are subclasses of Tiles that represent collections of them and
+ * therefore have an additional interfacial thickness parameter.
+ * 
+ * @author Jay Jay Billings, John Ankner
+ *
+ */
+public class Slab extends Tile {
+
+	/**
+	 * The interfacial width of the slab.
+	 */
+	public double interfaceWidth = 0.0;
+
+}