Fig. 4
Phonon identified in transmission electon microscopy (TEM) of tetracene. a TEM diffraction pattern of a single crystal tetracene at room temperature. False color image enhances the streaking pattern seen at 120. Scale bar shows 2 nm−1. b Motion vectors of the atoms for mode III. c Highest-occupied molecular orbital (HOMO) for the seven-molecule cluster at minimum (left) and maximum (right) molecular displacement of mode III, correlated with streaking in TEM. The purple arrows show the direction of molecular bending, red and green lines indicated the a and b axes, respectively
