diff --git a/src/apps/structure-info/model.ts b/src/apps/structure-info/model.ts
index 2cc19a45613210f720cd19807d81924d8ff7cf6c..17f1b6373892df00200857c438245b3dace4b97e 100644
--- a/src/apps/structure-info/model.ts
+++ b/src/apps/structure-info/model.ts
@@ -238,7 +238,6 @@ parser.addArgument(['--file', '-f'], { help: 'filename' });
 
 parser.addArgument(['--models'], { help: 'print models info', action: 'storeTrue' });
 parser.addArgument(['--seq'], { help: 'print sequence', action: 'storeTrue' });
-parser.addArgument(['--ihm'], { help: 'print IHM', action: 'storeTrue' });
 parser.addArgument(['--units'], { help: 'print units', action: 'storeTrue' });
 parser.addArgument(['--sym'], { help: 'print symmetry', action: 'storeTrue' });
 parser.addArgument(['--rings'], { help: 'print rings', action: 'storeTrue' });
diff --git a/src/mol-model/structure/model/model.ts b/src/mol-model/structure/model/model.ts
index e83ed86d3591283395a1efce657fe0d9a57d0acf..868f7e8a402799d7d51b7478b46f5ecd0f5edbc9 100644
--- a/src/mol-model/structure/model/model.ts
+++ b/src/mol-model/structure/model/model.ts
@@ -38,10 +38,11 @@ interface Model extends Readonly<{
     atomicConformation: AtomicConformation,
 
     properties: {
-        // secondary structure provided by the input file
+        /** secondary structure provided by the input file */
         readonly secondaryStructure: SecondaryStructure,
-        // maps modified residue name to its parent
+        /** maps modified residue name to its parent */
         readonly modifiedResidueNameMap: Map<string, string>,
+        /** maps asym ids to serial numbers that are unique per asym id */
         readonly asymIdSerialMap: Map<string, number>
     },
 
diff --git a/src/mol-model/structure/model/properties/utils/coarse-keys.ts b/src/mol-model/structure/model/properties/utils/coarse-keys.ts
index da591779c8d5c17a111c7686686cd78b2156e127..8ea3f848ca2a2117f11df7f6f41cbcec68318462 100644
--- a/src/mol-model/structure/model/properties/utils/coarse-keys.ts
+++ b/src/mol-model/structure/model/properties/utils/coarse-keys.ts
@@ -31,6 +31,7 @@ function createLookUp(entities: Entities, chain: Map<number, Map<string, number>
         if (!cm.has(c)) return -1;
         return cm.get(c)!;
     }
+    // TODO consider implementing as binary search
     const findSequenceKey: CoarsedElementKeys['findSequenceKey'] = (e, c, s) => {
         const eKey = getEntKey(e);
         if (eKey < 0) return -1;