Young's modulus along the thickness direction was measured by nanoindentation (Nano Indenter G200, TOYO Corporation), loading on the largest face. The loading rate was 0.03 mN/s, and the hold time at the peak load (1 mN) was 10 s. The samples were fixed with glue on the glass plate. Five measurements at different positions were performed for each crystal. The indenter was a Berkovich indenter with a triangular pyramid structure made of diamond. The obtained P-h curves were analyzed using the standard Oliver-Pharr method to determine Young's modulus. Young's modulus along the longitudinal direction was measured by bending test with a universal testing machine (RTG-1210, A&D). The bending test was repeated on different two or three crystals of each compound to calculate the average value. Workflow of this research. Machine learning (ML) was used to find the relationship of Young's modulus and functional groups, and to find the optimal experimental condition. Human task is to prepare for crystal samples, and to perform experiments at suggested conditions in real world.