  We present a generator of virtual molecules that selects valid chemistry on
the basis of the octet rule. Also, we introduce a mesomer group key that allows
a fast detection of duplicates in the generated structures.
  Compared to existing approaches, our model is simpler and faster, generates
new chemistry and avoids invalid chemistry. Its versatility is illustrated by
the correct generation of molecules containing third-row elements and a
surprisingly adept handling of complex boron chemistry.
  Without any empirical parameters, our model is designed to be valid also in
unexplored regions of chemical space. One first unexpected finding is the high
prevalence of dipolar structures among generated molecules.
