[gmx-users] error message

[Maria Sabaye Moghaddam]

Hi; 

 I am getting an error message as follows:

WARNING 1 [file "1s9z.top", line 39]:
  System has non-zero total charge: 3.000000e+00

processing coordinates...
double-checking input for internal consistency...
ERROR: One of the box vectors is shorter than twice the cut-off length.
Increase the box size or decrease rcoulomb.
Velocities were taken from a Maxwell distribution at 300 K
There was 1 warning
Fatal error: There was 1 error

Has anyone encountered this before?

Thanks, 
Maria.