Jmol has internal criteria based on atomic radii for auto-connecting atoms (bonds).
bondTolerance and minBondDistance allow some modification, and specific distance
ranges can also be specified. But it would be good to be able to specify a fractional
range eg 0.8 to 1.2 of the sum of the pairs of atomic or ionic radii, perhaps
connect 0.8 1.2 ionic (~cations) (~anions);
connect 0.8 1.2 atomic (~cations) (~anions);
where "ionic" means use ionic radii, and "atomic" use atomic radii.
The use of ionic radii is essential for most inorganic structures.