Dear Gromacs user, I was wondering why no .mtx file as hessian file was produced in my gmx mdrun? I used below command to submit my mdrun job: gmx mdrun -deffnm md -s md.tpr -mtx hessian.mtx -ntomp 4 -ntmpi 4 neither md.mtx nor hessian.mtx!? Cheers, Alex