[en] A new approach to search for materials with auxetic properties by modifying structures of solids at molecular level has been proposed. The analysis of elastic properties of the face-centered cubic Yukawa crystals with very narrow nanochannels in the [001] crystallographic direction using Monte Carlo simulations in the isothermal–isobaric ensemble has been done. An influence of the size of nanochannels on the value of Poisson’s ratio in main crystallographic directions has been studied. It has been shown that the insertion of nanochannels in the system causes a decrease of the Poisson’s ratio in the direction $[110][1\stackrel{¯<!--\; ??\; -->}{1}0]$ from –0.15(2) to –0.29(3). That means an amplification of auxetity in the studied system twice as compared to the system without nanochannels. (paper)