diff --git a/src/mol-geo/geometry/mesh/mesh.ts b/src/mol-geo/geometry/mesh/mesh.ts
index ed8f545de24e0a50e801795dbb896fc3f816f36d..255cff2ccf44657d55ebec116ba4e714aef29805 100644
--- a/src/mol-geo/geometry/mesh/mesh.ts
+++ b/src/mol-geo/geometry/mesh/mesh.ts
@@ -80,7 +80,7 @@ export namespace Mesh {
             Vec3.fromArray(y, v, b);
             Vec3.fromArray(z, v, c);
             Vec3.sub(d1, z, y);
-            Vec3.sub(d2, y, x);
+            Vec3.sub(d2, x, y);
             Vec3.cross(n, d1, d2);
 
             normals[a] += n[0]; normals[a + 1] += n[1]; normals[a + 2] += n[2];
diff --git a/src/mol-geo/representation/structure/visual/gaussian-surface-mesh.ts b/src/mol-geo/representation/structure/visual/gaussian-surface-mesh.ts
index 59485b6727f1f20830516cdd34265b523ef608ae..6c9cb6e048cd2d63026a5b067988d556303fd102 100644
--- a/src/mol-geo/representation/structure/visual/gaussian-surface-mesh.ts
+++ b/src/mol-geo/representation/structure/visual/gaussian-surface-mesh.ts
@@ -32,8 +32,6 @@ async function createGaussianSurfaceMesh(ctx: RuntimeContext, unit: Unit, struct
 export const DefaultGaussianSurfaceProps = {
     ...DefaultUnitsMeshProps,
     ...DefaultGaussianDensityProps,
-
-    flipSided: true, // TODO should not be required
 }
 export type GaussianSurfaceProps = typeof DefaultGaussianSurfaceProps