Linear spin-(1/2 magnetic chains: Susceptibilities, correlation functions, and applications to (${\mathrm{C}}_6$${\mathrm{H}}_{11}$${\mathrm{NH}}_3$)${\mathrm{CuBr}}_3$ and deuterated ${\mathrm{CuCl}}_2$⋅2(${\mathrm{CH}}_3$${)}_2$SO

The susceptibilities, correlation functions, and correlation length of the spin-(1/2 one-dimensional XXZ model are calculated for the chains with the finite size N and free boundary conditions. The infinite-chain results are estimated by extrapolation in 1/N, and good convergence is found for most temperatures. Theoretical estimates are compared with the experimental results for the corresponding model compounds ${\mathrm{C}}_6$ ${\mathrm{H}}_{11}$ ${\mathrm{NH}}_3$ ${\mathrm{CuBr}}_3$ (CHAB-$d_{14}$) and ${\mathrm{CuCl}}_2$⋅2(${\mathrm{CH}}_3$ ${)}_2$SO (CDC) in the deuterated versions. The crossover region of the in-plane correlation functions is revealed and the inverse correlation length is in a semiquantitative agreement with that measured for CHAB. The single-crystal magnetic susceptibility data for CDC are reinterpreted and the quantitative agreement with the experiment is found.