Figure 7.
Free energy profile corresponding to the flexible behavior of CAU-13 at 300 K obtained with various enhanced sampling methods and as a function of three different collective variables: (a) the unit cell volume, (b) the dihedral angles ϕi, and (c) the bending angles γi. The profiles shown in panes (b) and (c) are obtained by a projection of a 2D free energy surface. A distinction is made between the techniques enhancing along those collective variables (TI, US, and VES) and enhancing all degrees of freedom (RE). Based on the transformation outlined in eq 1, free energy profiles as a function of the unit cell volume and bending angles can be constructed starting from the free energy profile for the dihedral angles. These transformed profiles, US(T) and VES(T), are indicated with dotted lines.