diff --git a/src/mol-geo/primitive/cage.ts b/src/mol-geo/primitive/cage.ts
index 3fad311d5addffe280af4a58bf410d25ca7cdd04..8911c1ece86db5184dc2ccd256555a2252799a2d 100644
--- a/src/mol-geo/primitive/cage.ts
+++ b/src/mol-geo/primitive/cage.ts
@@ -16,7 +16,7 @@ export function createCage(vertices: ArrayLike<number>, edges: ArrayLike<number>
     return { vertices, edges }
 }
 
-export function copyCage(cage: Cage): Cage {
+export function cloneCage(cage: Cage): Cage {
     return {
         vertices: new Float32Array(cage.vertices),
         edges: new Uint32Array(cage.edges)
diff --git a/src/mol-geo/primitive/tetrahedron.ts b/src/mol-geo/primitive/tetrahedron.ts
index fd89bf8e118636b3b7efa934461e57eca1549dd9..f43c372417d9a503c1b1d31e745a2aaf3f1b27b6 100644
--- a/src/mol-geo/primitive/tetrahedron.ts
+++ b/src/mol-geo/primitive/tetrahedron.ts
@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2019 mol* contributors, licensed under MIT, See LICENSE file for more info.
+ * Copyright (c) 2019-2020 mol* contributors, licensed under MIT, See LICENSE file for more info.
  *
  * @author Alexander Rose <alexander.rose@weirdbyte.de>
  */
@@ -8,20 +8,16 @@ import { createPrimitive, Primitive } from './primitive';
 import { createCage, Cage } from './cage';
 
 export const tetrahedronVertices: ReadonlyArray<number> = [
-    0.7071, 0, 0,  -0.3535, 0.6123, 0,  -0.3535, -0.6123, 0,
-    0, 0, 0.7071,  0, 0, -0.7071
-
+    0.5, 0.5, 0.5,  -0.5, -0.5, 0.5,  -0.5, 0.5, -0.5,  0.5, -0.5, -0.5
 ];
 
 export const tetrahedronIndices: ReadonlyArray<number> = [
-    4, 1, 0,  4, 2, 1,  4, 0, 2,
-    0, 1, 3,  1, 2, 3,  2, 0, 3,
+    2, 1, 0,  0, 3, 2,  1, 3, 0,  2, 3, 1
 ];
 
 const tetrahedronEdges: ReadonlyArray<number> = [
     0, 1,  1, 2,  2, 0,
     0, 3,  1, 3,  2, 3,
-    0, 4,  1, 4,  2, 4,
 ]
 
 let tetrahedron: Primitive
diff --git a/src/mol-plugin/util/model-unitcell.ts b/src/mol-plugin/util/model-unitcell.ts
index 7ec657b580031ccb20ea5191e37e75c4043b7b83..def1a033b60a822e853d63967424ae78d81ff547 100644
--- a/src/mol-plugin/util/model-unitcell.ts
+++ b/src/mol-plugin/util/model-unitcell.ts
@@ -14,11 +14,11 @@ import { Mesh } from '../../mol-geo/geometry/mesh/mesh';
 import { MeshBuilder } from '../../mol-geo/geometry/mesh/mesh-builder';
 import { BoxCage } from '../../mol-geo/primitive/box';
 import { Mat4, Vec3 } from '../../mol-math/linear-algebra';
-import { transformCage, copyCage } from '../../mol-geo/primitive/cage';
+import { transformCage, cloneCage } from '../../mol-geo/primitive/cage';
 import { radToDeg } from '../../mol-math/misc';
 
 const translate05 = Mat4.fromTranslation(Mat4(), Vec3.create(0.5, 0.5, 0.5))
-const unitCage = transformCage(copyCage(BoxCage()), translate05)
+const unitCage = transformCage(cloneCage(BoxCage()), translate05)
 
 const tmpRef = Vec3()
 const tmpTranslate = Mat4()
@@ -43,7 +43,7 @@ function getUnitcellMesh(data: UnitcellData, props: UnitcellProps, mesh?: Mesh)
 
     Vec3.floor(tmpRef, data.ref)
     Mat4.fromTranslation(tmpTranslate, tmpRef)
-    const cellCage = transformCage(copyCage(unitCage), tmpTranslate)
+    const cellCage = transformCage(cloneCage(unitCage), tmpTranslate)
 
     const radius = (Math.cbrt(data.symmetry.spacegroup.cell.volume) / 300) * props.cellScale
     state.currentGroup = 1