GARANT COMMANDS: define secondary shifts - define shifts based on 2nd structure

usage: define secondary shifts <read(.txt)>

Secondary structure specific chemical shifts are defined based on the 
secondary structure specified in the file <read(.txt)> and the chemical
shifts defined in the library .../lib/shifts.lib. The secondary structure
elements currently defined in the library are 'helix', 'sheet', and 'coil'.
The secondary structure file has to contain a line for each residue with
known secondary structure that starts with
   <nr> <restype>  <sectype>
where <nr> and <restype> are the number and the type of the residue, and
<spectype> the secondary structure type. E.g.,

 32 PRO  helix (helix_alpha, helix2)
 33 GLY  helix (helix_alpha, helix2)
 34 MET  helix (helix_alpha, helix2)
 35 TYR  helix (helix_alpha, helix2)
 36 ILE  helix (helix_alpha, helix2)
...
135 SER  sheet

defines residues 32 to 36 to be helical, and 135 to lie in a beta-sheet. Such
files can be generated with the program MOLMOL (Koradi et al.).

see also: make coherences, coherences