subroutine check_bond
C Subroutine is checking if the fitted function which describs sc_rot_pot
C is correct, printing, alpha,beta, energy, data - for some known theta. 
C theta angle is read from the input file. Sc_rot_pot are printed 
C for the second  residue in sequance.
       include 'DIMENSIONS'
       include 'COMMON.VAR'
       include 'COMMON.GEO'
       include 'COMMON.INTERACT'
       include 'COMMON.CHAIN'
       double precision energia(0:n_ene)
       it=itype(2)
       do i=1,101
         vbld(nres+2)=0.5d0+0.05d0*(i-1)
         call chainbuild
         call etotal(energia)
         write (2,*) vbld(nres+2),energia(17)
       enddo
       return
       end