An atom must be pruned if its subvalence is zero. If the atom's charge is non-zero, the default valences for the isoelectronic element are used to compute subvalence. If there are no such target valences (e.g., [c+2]), an error must be generated. Writers must not write such atoms.
An atom must be pruned if its subvalence is zero. If the atom's charge is non-zero, the default valences for the isoelectronic element are used to compute subvalence. If there are no such target valences (e.g.,
[c+2]), an error must be generated. Writers must not write such atoms.