[gmx-users] Minimization error

[Abid Channa]

Dear Gromacs users,
I am running simulation of apo  protein. In minimization step when I am running this command    " gmx mdrun -v -deffnm em"  the error appears that 
" Fatal error:
There is no domain decomposition for 24 ranks that is compatible with the given box and a minimum cell size of 3.96993 nm
Change the number of ranks or mdrun option -rdd ".
Kindly give your valuable suggestions for handling this error.
Kind Regards,
 
Abid Ali Channa,
Junior Research Fellow,
Lab No.  P-133, Computational Chemistry Unit,
 Dr .Panjwani Center for Molecular Medicine and Drug Research (PCMD),
 International Center for Chemical and Biological Sciences  (ICCBS),
 University of Karachi-75270.Karachi-Pakistan.UAN # (92-21) 111-222-292 Ext. (309)
             Cell # +923013553051.
http://www.iccs.edu/