  The molar spin susceptibilities $\chi(T)$ of Na-TCNQ, K-TCNQ and Rb-TCNQ(II)
are fit quantitatively to 450 K in terms of half-filled bands of three
one-dimensional Hubbard models with extended interactions using exact results
for finite systems. All three models have bond order wave (BOW) and charge
density wave (CDW) phases with boundary $V = V_c(U)$ for nearest-neighbor
interaction $V$ and on-site repulsion $U$. At high $T$, all three salts have
regular stacks of $\rm TCNQ^-$ anion radicals. The $\chi(T)$ fits place Na and
K in the CDW phase and Rb(II) in the BOW phase with $V \approx V_c$. The Na and
K salts have dimerized stacks at $T < T_d$ while Rb(II) has regular stacks at
100K. The $\chi(T)$ analysis extends to dimerized stacks and to dimerization
fluctuations in Rb(II). The three models yield consistent values of $U$, $V$
and transfer integrals $t$ for closely related $\rm TCNQ^-$ stacks. Model
parameters based on $\chi(T)$ are smaller than those from optical data that in
turn are considerably reduced by electronic polarization from quantum chemical
calculation of $U$, $V$ and $t$ on adjacent $\rm TCNQ^-$ ions. The $\chi(T)$
analysis shows that fully relaxed states have reduced model parameters compared
to optical or vibration spectra of dimerized or regular $\rm TCNQ^-$ stacks.
