double precision c,dc,dc_old,d_c_work,xloc,xrot,dc_norm,t,r,
& prod,rt,dc_work,cref,crefjlee,chain_rep,dc_norm2
common /chain/ c(3,maxres2+2),dc(3,0:maxres2),dc_old(3,0:maxres2),
double precision c,dc,dc_old,d_c_work,xloc,xrot,dc_norm,t,r,
& prod,rt,dc_work,cref,crefjlee,chain_rep,dc_norm2
common /chain/ c(3,maxres2+2),dc(3,0:maxres2),dc_old(3,0:maxres2),