usr/src/local/ditroff/ditroff.okeeffe/chem/morphine.p

.cstart
# This is a structure of morphine, for comparison with the one
# in the preprint by Broadbent and Norris
#
R1:     ring6 double 1,2
        bond -60 from R1.V6 ; HO
R2:     ring6 with .V1 at R1.V3
        bond 60 from R2.V2 ; N
        bond right from N ; CH3
R3:     benzene with .V1 at R2.V5
        bond -120 from R3.V5 ; HO
# this is the furan ring
        bond -135 length .3 from R1.V5 ; O
        bond -45 length .3 from R3.V6
# this is the odd ring
        bond up length .1 from N ; BP
B1:     bond up length .35 from R1.V4
        bond to BP
.cend