Gen_vel=no and continuation=false

GROMACS version: 2023.4
GROMACS modification: No
I’m performing a 10μs simulation divided into 50 simulations of 200ns each. I set ‘gen_vel=no’ in the mdp file, but I didn’t include ‘continuation=yes’. The simulations are working, but I can’t understand how GROMACS generates velocities. Also i didn’t include the grompp -f .cpt flag.

gmx grompp -f md_0mV.mdp -c md_0mV-001.gro -r md_0mV-001.gro -p …/ -n …/index.ndx -o md_0mV-002.tpr
gmx mdrun -v -deffnm md_0mV-002 -ntmpi 1 -nt 10 -nb gpu
Thank you everybody!

The continuation option does not affect velocity generation. It controls whether the initial coordinates and velocities are constrained and whether the state of thermo- and barostat, when present, are taking from the checkpoint file (which you do not pass).