diff --git a/polytopes.js b/polytopes.js
index 15c6d2f..a1156e8 100644
--- a/polytopes.js
+++ b/polytopes.js
@@ -58,16 +58,15 @@ export function auto_detect_edges(nodes, neighbours, debug=false) {
 // too small and simple to calculate
 
 export const cell5 = () => {
-	const r5 = Math.sqrt(5);
-	const r2 = Math.sqrt(2) / 2;
+	const c1 = Math.sqrt(5) / 4;
 	return {
 		name: '5-cell',
 		nodes: [
-	      {id:1, label: 1, x: r2, y: r2, z: r2, w: -r2 / r5 },
-	      {id:2, label: 2, x: r2, y: -r2, z: -r2, w: -r2 / r5 },
-	      {id:3, label: 3, x: -r2, y: r2, z: -r2, w: -r2 / r5 },
-	      {id:4, label: 4, x: -r2, y: -r2, z: r2, w: -r2 / r5 },
-	      {id:5, label: 5, x: 0, y: 0, z: 0, w: 4 * r2 / r5 },
+	      {id:1, label: 1, x: c1, y: c1, z: c1, w: -0.25 },
+	      {id:2, label: 2, x: c1, y: -c1, z: -c1, w: -0.25 },
+	      {id:3, label: 3, x: -c1, y: c1, z: -c1, w: -0.25 },
+	      {id:4, label: 4, x: -c1, y: -c1, z: c1, w: -0.25 },
+	      {id:5, label: 5, x: 0, y: 0, z: 0, w: 1 },
 		],
 		links: [
 			{ id:1, source:1, target: 2},
@@ -109,7 +108,7 @@ export const cell16 = () => {
 	nodes[1].label = 4;
 
 	index_nodes(nodes);
-	scale_nodes(nodes, 0.75);
+	scale_nodes(nodes, 0.5);
 	const links = auto_detect_edges(nodes, 6);
 
 	return {
@@ -767,4 +766,8 @@ export const build_all = () => {
 	 	cell120_inscribed(),
 	 	cell120_layered()
 	 	];
+}
+
+export const radii = (shape) => {
+	return shape.nodes.map(n => Math.sqrt(n.x * n.x + n.y * n.y + n.z * n.z + n.w * n.w))
 }
\ No newline at end of file