Hi everybody, I'm using SiteComp to detect differences in binding affinities between two similar structures. The _clusters.pdb file produced by SiteComp is a standard PDB file in which the grid points corresponding to the difference clusters are represented by hydrogen atoms. They can be treated as any molecule in Chimera. Usually I find it useful to represent them as a mesh surface. Usually, I load in Chimera the protein.pdb, the ligand.pdb and the _clusters.pdb. After this, I select the _clusters.pdb and show it as mesh or solid using Actions-> Surface. In some cases, I fail to render the surface, or to be precise only one part of the clusters is rendered. I understand that this is a frequent problem with this type of discontinuous pdb. I'm attaching one such file and I would be grateful for any help Best regards George