NAME
     CalcSecondary - calculate secondary structure

SYNOPSIS
     CalcSecondary

DESCRIPTION
     Calculate the secondary structure of a protein
     using the algorithm published by Kabsch/Sander.
     The command operates on all selected residues
     of all selected molecules. It will set various
     properties on these residues, depending on the
     secondary structure. These properties are listed
     in a text window. They are used by the AddRibbon
     command to produce schematic drawings.

     Note that editing the text has no effect on the
     definitons used. For changing the definitons it
     is most convenient to use the WriteSecondary
     command.

     Since the calculation is based on hydrogen bonding
     patterns, the coordinates of HN atoms are required.
     So before using the command for a structure without
     coordinates for hydrogen atoms (X-ray), use the
     CalcAtom command for adding them.

EXAMPLE
     CalcSecondary

SEE ALSO
     SelectMol, SelectRes, CalcAtom,
     DefPropRes, WriteSecondary, AddRibbon

DATE
     960815
