message: get boundary from unit (not lookup)
diff: @@ -26,7 +26,7 @@ export function computeStructureBoundary(s: Structure): Boundary {
  for (let i = 0, _i = units.length; i < _i; i++) {
  const u = units[i];
  - const invariantBoundary = u.lookup3d.boundary;
  + const invariantBoundary = u.boundary;
  const o = u.conformation.operator;
  if (o.isIdentity) {
  @@ -41,7 +41,7 @@ export function computeStructureBoundary(s: Structure): Boundary {
  for (let i = 0, _i = units.length; i < _i; i++) {
  const u = units[i];
  - const invariantBoundary = u.lookup3d.boundary;
  + const invariantBoundary = u.boundary;
  const o = u.conformation.operator;
  if (o.isIdentity) {
  