{'fraction_non_alphanumeric': 0.022658610271903322, 'fraction_numerical': 0.0256797583081571, 'mean_word_length': 4.867256637168142, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Strain dependence of the vibrational modes of a diacetylene crystal

Resonance Raman spectroscopy has been used to measure the strain dependence of four high-frequency vibrational modes in a single crystal of toluene sulfonate diacetylene polymer. The 0.62-μm thick crystal was stretched elastically to 4% strain before fracture occurred. This was equivalent to an ultimate tensile strength of 2.0 × 109 N m−2. The strain dependence of the vibrational modes has been interpreted using a simple point mass and anharmonic spring constant model. A Fermi resonance was observed for two vibrational modes which are degenerate at 2.1% strain and a 1464 cm−1 frequency.