10.1021/ja4102634.s004 Guangfeng Liu Guangfeng Liu Jie Liu Jie Liu Yang Liu Yang Liu Xutang Tao Xutang Tao Oriented Single-Crystal-to-Single-Crystal Phase Transition with Dramatic Changes in the Dimensions of Crystals American Chemical Society 2014 Dramatic Changes Dimensions crystal dimensions Oriented CrystalsWe report cocrystal phenomenon polymorph CuQ basis pattern mechanism thickness Phase Transition ambient conditions convert transition analysis length phase stimulation 2014-01-15 00:00:00 Media https://acs.figshare.com/articles/media/Oriented_Single_Crystal_to_Single_Crystal_Phase_Transition_with_Dramatic_Changes_in_the_Dimensions_of_Crystals/2332201 We report here a new polymorph of cocrystal CuQ<sub>2</sub>-TCNQ that shows an oriented single-crystal-to-single-crystal phase transition along its <i>a</i>-axis at ambient conditions. Upon mechanical stimulation, it converts into another polymorph accompanied by almost doubling its length and halving its thickness. Our crystallographic studies indicate the dramatic changes in crystal dimensions resulted from the prominent changes of molecular stacking patterns. A reasonable mechanism for the phenomenon was proposed on the basis of the structural, microscopic, and thermal analysis.