Update open source between_residue_clash_loss to take into account mu…

…ltiple chains.

PiperOrigin-RevId: 432934821
Change-Id: If5decaf654823a37c4270151039a12606f526f7a

alphafold/model/all_atom_multimer.py

@@ -598,6 +598,7 @@ def between_residue_clash_loss(
     atom_exists: jnp.ndarray,  # (N, 14)
     atom_radius: jnp.ndarray,  # (N, 14)
     residue_index: jnp.ndarray,  # (N)
+    asym_id: jnp.ndarray,  # (N)
     overlap_tolerance_soft=1.5,
     overlap_tolerance_hard=1.5) -> Dict[Text, jnp.ndarray]:
   """Loss to penalize steric clashes between residues."""
@@ -624,8 +625,9 @@ def between_residue_clash_loss(
   # Backbone C--N bond between subsequent residues is no clash.
   c_one_hot = jax.nn.one_hot(2, num_classes=14)
   n_one_hot = jax.nn.one_hot(0, num_classes=14)
-  neighbour_mask = ((residue_index[:, None, None, None] +
-                     1) == residue_index[None, :, None, None])
+  neighbour_mask = ((residue_index[:, None] + 1) == residue_index[None, :])
+  neighbour_mask &= (asym_id[:, None] == asym_id[None, :])
+  neighbour_mask = neighbour_mask[..., None, None]
   c_n_bonds = neighbour_mask * c_one_hot[None, None, :,
                                          None] * n_one_hot[None, None, None, :]
   dists_mask *= (1. - c_n_bonds)

alphafold/model/folding_multimer.py

@@ -664,7 +664,8 @@ def loss(self,
         residue_index=residue_index,
         mask=pred_mask,
         pred_positions=pred_positions,
-        config=self.config)
+        config=self.config,
+        asym_id=batch['asym_id'])
 
     sidechains = value['sidechains']
 
@@ -890,7 +891,8 @@ def find_structural_violations(
     residue_index: jnp.ndarray,
     mask: jnp.ndarray,
     pred_positions: geometry.Vec3Array,  # (N, 14)
-    config: ml_collections.ConfigDict
+    config: ml_collections.ConfigDict,
+    asym_id: jnp.ndarray,
     ) -> Dict[str, Any]:
   """Computes several checks for structural Violations."""
 
@@ -921,7 +923,8 @@ def find_structural_violations(
       atom_radius=atom_radius,
       residue_index=residue_index,
       overlap_tolerance_soft=config.clash_overlap_tolerance,
-      overlap_tolerance_hard=config.clash_overlap_tolerance)
+      overlap_tolerance_hard=config.clash_overlap_tolerance,
+      asym_id=asym_id)
 
   # Compute all within-residue violations (clashes,
   # bond length and angle violations).