Figure 11
From: The effect of temperature and pressure on the crystal structure of piperidine
The effects of a 5% reduction in the a and c axis lengths on intermolecular contact energies. The energies were calculated for different model structures using the PIXEL method. Model ‘opt’ refers to the structure at 0.22 GPa after optimisation of the coordinates using DFT (holding the cell dimensions fixed). Model ‘A’ was obtained from model ‘opt’ by reducing the length of the a-axis by 5% and re-optimising the structure. Model ‘C’ was obtained in a similar way, but after reducing the length of the c-axis by 5%. The Figures 3 and 5 etc. on the right of the figure refer to the contact numbers listed on the far left of Table 2. Contacts 4, 6, 10 and 12 are symmetry equivalent to those shown. The H-bond contacts 1 and 2 are omitted for clarity.