SCatmMiss ?

$>$ x.SCatmMiss()
This will return the number of amino-acid residues having some side chain missing atom, and a string containing the information about all the residues with missing side chain atoms. For each residue, the string consists of RName_ChLbl_RNum_RIcode, where RName is the name of the residue (3 letters), ChLbl is the chain label, RNum is the number of the residue (as in the PDB file) and RIcode the PDB insertion code of the residue.