LAMMPS error using reax/C

I stand corrected: extracting elastic modulus from the beginning portion of the elastic regime is absolutely valid and that is usually how elastic constants are measured. The main area of improvement for your results is that you should examine how your results change with strain rate. With 1e-5 strain rate, are you sure you are not generating a shock wave? ReaxFF can certainly predict the mechanical properties if the particular forcefield is well-fitted.

Hi Ray,

Just wanted to follow up on this in case other users were reading and wanted to know my results. When running with the small time step (0.001fs) and very fast strain rate (0.01 per fs) showed no issues when viewed on ovito, and best predicted the elastic modulus with a very linear stress strain curve. This leads me to believe that in the early part of the elastic portion of a stress strain curve sampling the modulus from a fast strain rate appears appropriate.

Thanks again for your patience on this exercise!

Liam