[gmx-users] grompp bug (system charge)

[Christoph Freudenberger]

hi there,

There seems to be a bug in the way grompp calculates the total
charge of the system.
For my box (9 kations/9 anions/some 10000 solvents) grompp prints
out a warning:
WARNING 4 [file "topol.top", line 22]:
   System has non-zero total charge: 7.999992e+00

I dublechecked the charges in the resulting tpr using the following
command-pipe:
 > gmxdump -s test.tpr |grep "atom\["|awk -F, '{print $5}'|awk -F= '{sum+=$2}END{print sum}'

and get:
-2.55351e-15
which is neutral to me.
-- 
Christoph Freudenberger
Abt. Organische Chemie I AK Siehl - Uni Ulm -Tel: ++49-731-502-2785