k , into a distorted grid around the second structure, G Let us use the transformation of three acetylene molecules to benzene as an example to illustrate what a mapped grid should look like. The top panel of Fig. shows a rectangular grid (with a 0.1 Å grid size) around three acetylene molecules arranged in a hexagonal complex. Clearly, there are fewer grid points between the two carbon atoms within each acetylene molecule (separated by 1.215 Å) than between the closest carbon atoms from neighboring molecules (distance: 2.410 Å). As the distance between the acetylene molecules shortens to 1.398 Å (which is the equilibrium C-C bond length of benzene), we expect the grid points between these molecules to be squeezed closer to each other, as shown in the bottom panel of Fig. . Meanwhile, the C-C bond within each acetylene molecule gets stretched, so one would expect a larger spacing between the grid points between the two carbon atoms of each acetylene molecule. There might be different ways for carrying out such mapping of a rectangular grid into a distorted one. In this work, we will utilize a continuous reaction pathway R A (s) that connects the two stationary structures, R (0) A (s=0) and R