The standard enthalpies of formation ΔH°f[naphthalene TCNQ(c), 298.15 K]=716.95±7.30 kJ/mol, ΔH°f[anthracene TCNQ(c), 298.15 K] =763.84±4.87 kJ/mol, and ΔH0f[TMPD(c), 298.15 K]=39.60±3.85 kJ/mol were measured by oxygen combustion calorimetry. Then, the states naphthalene TCNQ(c), anthracene TCNQ(c), and TMPD TCNQ(c) are more stable by 30.01±7.63, 30.31±5.26, and 82.08±4.34 kJ/mol than the states [naphthalene(c), TCNQ(c)], [anthracene(c), TCNQ(c)], and [TMPD(c), TCNQ(c)], respectively; they are more stable than the gaseous neutral ions by 203±12, 232±12, and 230±10 kJ/mol, respectively. Therefore, the choices of different lattices and ionicities are determined not by the thermochemical results given above, but by a subtle interplay between the cost of ionization ID–AA and the various charge-dependent contributions to the theoretical cohesive energy.