The Poisson’s ratio of two-dimensional hexagonal crystals has been widely studied due to its fundamental and fantastic nature. However, the issue involved in the regulation strategy and in the bounds of Poisson’s ratio of two-dimensional hexagonal crystals has not been addressed. In this work, we predict that the Poisson’s ratio of two-dimensional hexagonal crystals can be controlled by modifying the structural interaction therein, where the lower bound and upper bound are $-1∕3$ and $+1$, respectively. Furthermore, molecular simulations verify these predictions. Finally, the underlying mechanism is revealed as the interplay between two deformation modes (i.e., bond stretching and angle changing). This work provides an universal regulation strategy to tune the Poisson’s ratio of two-dimensional hexagonal crystals, and determines fundamental limits on the Poisson’s ratio of two-dimensional hexagonal crystals.

二维六方晶体的泊松比由于其基本性质和奇异性质而被广泛研究。但是，尚未解决调节策略和二维六方晶体的泊松比范围内的问题。在这项工作中，我们预测二维六角形晶体的泊松比可以通过修改其中的结构相互作用来控制，其中下界和上限是$-\mathrm{1个}∕3$ 和 $+\mathrm{1个}$， 分别。此外，分子模拟验证了这些预测。最后，潜在的机理被揭示为两种变形模式（即，粘结拉伸和角度变化）之间的相互作用。这项工作提供了一种通用的调节策略来调整二维六角形晶体的泊松比，并确定了二维六角形晶体的泊松比的基本限制。