Minimization

Presumably you have an appropriately created geo file as a starting structure.

In the control file, make sure that imetho is set to 1.

In the MM parameters section, most of the default values work well. Here are the key ones and what they mean.
    1.00000  endmm  - this is a good convergence criteria (no need to change)
            000  imaxmo  - use the conjugate gradient minimization scheme
            500  maxit  - run for 500 iterations (you might need longer if your starting structure is far from optimal)
            500  iout4  - usually set to the same value as maxit since you don't need the geometries in between
    1.00000  cellopt  - don't change the cell parameters during the optimization

You can look at fort.57 to monitor how the minimization run is going. The value of RMSG needs to go below endmm for the structure to be successfully minimized.

The final structure at the end of the minimization is fort.90

If the geometry hasn't optimized and you hit maxit number of steps, you can just continue the minimization by copying fort.90 (the latest structure) into geo and rerunning the minimization.

When you're done, copy the fort.90 file to the directory where you'll be running your dynamics simulations, and rename it geo since it is now the new starting structure for the dynamics run.