1 The unstated rationale for favoring Allen's scale of electronegativity seems to be that it maintains the connection with ionization energy that is used by the authors to develop shell structure, but this is hardly a compelling reason for choosing Allen's particular function of ionization energies.
(1; seems; ) (this; is hardly; a compelling reason for choosing Allen's particular function of ionization energies) (ionization energy; is used; by the authors; to develop shell structure)
1 this ionization energy
seems is hardly is used
a compelling reason for choosing Allen's particular function of ionization energies
by the authors to develop shell structure