i want calculate the aggregate behavior of asphaltene ，and it failed when i set 10 Angstrom as the cutoff ，1fs as the time step。

run the NPT MD ，it cannot work and with this warings：

Warning the calculated value of the energy may not be reliable,

as the charge groups are large relative to the cutoff.

Try reducing the charge group size or use a cutoff of at least 29 Angstroms.

when i change the cutoff for 30 Angstrom，and it failed as well。

Dynamics calculation - Aborting dynamics.

An unphysical integration step (>100 Angstroms) has been detected.

Try relaxing the structure with geometry optimization, reducing the time step,

reducing the temperature or a combination of these.

although l reduce the time step ，it cannot work 。geometry optimization was run before NPT MD。

wish for your replay