CARBon {<chemical-shift-statement>} END
   ASSIgn <sel> <sel> <sel> <sel> <sel> <real> <real>
   {* Ci-1, Ni, Cai, Ci, Ni+1, Ca-obs, Cb-obs (in ppm) *}
   CLASsification <name> ! Starts a new class. Applies to all
               ! ASSIgn and FORCe entries until another CLASs entry
               ! is issued.
   EXPEctation <integer> <integer> <real> <real> <real> <real>
               ! {* psi-pos psi-pos CAvalue CAerr CBvalue CBerr *}
               ! for expectation values
   FORCeconstant <real> ! force constant for all assignments
               ! in the current CLASs. (default: 50)
   NREStraints <integer> ! number of slots for chemical shift
               ! restraints to allocate in memory (default: 200)
   PHIStep <real> ! number of steps in the phi dimension of the
               ! expectation array
   PSIStep <real> ! number of steps in the psi dimension of the
               ! expectation array
   POTEntial <SQUAre | HARMonic> ! use shift errors or not
   PRINt THREshold <real> ! prints secondaray shift
               ! violations of either Ca or Cb
               ! greater than the specified value (in ppm)
               ! the following variables are set:
               !  RMSCA - rmsd of CA chem shifts
               !  RMSCB - rmsd of CB chem shifts
               !  RMSD  - a weighted average
               !  NUMBER- total number of shifts
               !  VIOLATIONS - number of violated restraints
   RCOIl <sel> <real> <real> ! set the random
               ! coil a and b 13C shifts for the selected atoms
   RESEt ! erases the chemical shift assignment table
   ZERO ! zero out the expectation value arrays

Xplor-NIH 2023-11-10