diffusion Cu/Cu(001) - reaxff + colvar

Dear lammps-users,

I want to perform metadynamics simulations of Cu/Cu(001) with reaxff ( in order to have an idea how to set CVs, work with output, etc).

I have already run the examples, and they ran without error. But with my input files for Cu/Cu(001) I became the following error message:


colvars: Non-dynamic feature : "lower boundary" in colvar one may not be enabled as a dependency.
colvars: ...required by "grid" in colvar one
colvars: Error: Failed dependency in colvar one.
ERROR on proc 0: Fatal error in the collective variables module.


I set to CVs : distance in X-axis and coordination number, I searched for the error message, but didn't find something (probably didn't get it)

I attached the input files.

hoping you could help me!

many thanks in advance,

diffusion.colvars (553 Bytes)

diffusion.data (2.24 KB)

in.diffusion (794 Bytes)

Hi Alexandra, unfortunately the error message of the code version that you are using may be confusing.

The gist of it is that by default metadynamics will need to tabulate the Gaussian functions onto a grid for computational efficiency and ease of visualization (the PMF will be written automatically). The grid parameters are then required for each variable: lowerBoundary, upperBoundary (self-explanatory) and width (the spacing of the grid).

Note also that “hillWidth” is usually not needed, and its units are relative to “width” because you are using together multiple variables that may have very different units. After setting “width”, you could use e.g. “hillWidth 1.0” or just not specify it.

Lastly, can you report the version of Colvars that you are using? It should be printed in the LAMMPS log.