diff --git a/src/mol-data/int/_spec/ordered-set.spec.ts b/src/mol-data/int/_spec/ordered-set.spec.ts
index 8cbad68ceb07cdb09f51398ebf61274f53b14cfc..a8f2a5d10c39c9f771c0d6da0eca81c299a39537 100644
--- a/src/mol-data/int/_spec/ordered-set.spec.ts
+++ b/src/mol-data/int/_spec/ordered-set.spec.ts
@@ -25,6 +25,7 @@ describe('ordered set', () => {
     const singleton10 = OrderedSet.ofSingleton(10);
     const range1_4 = OrderedSet.ofRange(1, 4);
     const arr136 = OrderedSet.ofSortedArray([1, 3, 6]);
+    const arr12369 = OrderedSet.ofSortedArray([1, 2, 3, 6, 9]);
 
     const iB = (s: number, e: number) => Interval.ofBounds(s, e);
 
@@ -47,6 +48,14 @@ describe('ordered set', () => {
         expect(OrderedSet.areIntersecting(empty, singleton10)).toBe(false);
         expect(OrderedSet.areIntersecting(empty, range1_4)).toBe(false);
         expect(OrderedSet.areIntersecting(empty, arr136)).toBe(false);
+
+        expect(OrderedSet.areIntersecting(Interval.ofRange(2, 3), arr12369)).toBe(true);
+        expect(OrderedSet.areIntersecting(Interval.ofRange(2, 6), arr12369)).toBe(true);
+        expect(OrderedSet.areIntersecting(Interval.ofRange(2, 8), arr12369)).toBe(true);
+        expect(OrderedSet.areIntersecting(Interval.ofRange(4, 8), arr12369)).toBe(true);
+
+        expect(OrderedSet.areIntersecting(Interval.ofRange(4, 5), arr12369)).toBe(false);
+        expect(OrderedSet.areIntersecting(Interval.ofRange(7, 8), arr12369)).toBe(false);
     });
 
     it('isSubset', () => {
diff --git a/src/mol-data/int/impl/ordered-set.ts b/src/mol-data/int/impl/ordered-set.ts
index 5688286a7f5937e159cd0bb689789255e1814e90..6031729daf7a67e650a617ca86a20a562081b139 100644
--- a/src/mol-data/int/impl/ordered-set.ts
+++ b/src/mol-data/int/impl/ordered-set.ts
@@ -29,6 +29,8 @@ export function indexOf(set: OrderedSetImpl, x: number) { return I.is(set) ? I.i
 export function getAt(set: OrderedSetImpl, i: number) { return I.is(set) ? I.getAt(set, i) : set[i]; }
 export function min(set: OrderedSetImpl) { return I.is(set) ? I.min(set) : S.min(set); }
 export function max(set: OrderedSetImpl) { return I.is(set) ? I.max(set) : S.max(set); }
+export function start(set: OrderedSetImpl) { return I.is(set) ? I.start(set) : S.start(set); }
+export function end(set: OrderedSetImpl) { return I.is(set) ? I.end(set) : S.end(set); }
 
 export function hashCode(set: OrderedSetImpl) { return I.is(set) ? I.hashCode(set) : S.hashCode(set); }
 // TODO: possibly add more hash functions to allow for multilevel hashing.
@@ -97,7 +99,10 @@ export function subtract(a: OrderedSetImpl, b: OrderedSetImpl) {
 function areEqualIS(a: I, b: S) { return I.size(a) === S.size(b) && I.start(a) === S.start(b) && I.end(a) === S.end(b); }
 
 function areIntersectingSI(a: S, b: I) {
-    return areRangesIntersecting(a, b);
+    if (S.size(a) === 0 || I.size(b) === 0) return false
+    const predAMinB = S.findPredecessorIndex(a, I.min(b))
+    const predAMaxB = S.findPredecessorIndex(a, I.max(b))
+    return predAMinB !== predAMaxB
 }
 
 function isSubsetSI(a: S, b: I) {