[gmx-users] Tip5p with gromos 96, error atom has mass 0

[主月 ：）]

Hi all:
I built a topol file for tip5p water accordint to tip5p.itp which is designed for OPLS.But when i used grompp to built a tpr file, three errors came even the system just have one tip5p water.

The error is :

ERROR 1 [file "topol.top", line 10]:
  atom OW <Res SOL-1> has mass 0
ERROR 2 [file "topol.top", line 10]:
  atom HW1 <Res SOL-1> has mass 0
ERROR 3 [file "topol.top", line 10]:
  atom HW2 <Res SOL-1> has mass 0

In fact, the mass for all above atoms were all defined in atp file. How can i fix it? Thanks a lot.

The build steps are follows:
1. Named the atom type in new tip5p.itp. Add them to ffG53a6.atp and ffG53a6nb.itp.
In tip5p.itp:
[ atoms ]
; id    at type res nr  residu name     at name         cg nr   charge
1       5p_O     1       SOL              OW             1       0
2       5p_H     1       SOL             HW1             1       0.241
3       5p_H     1       SOL             HW2             1       0.241
4       5p_L     1       SOL             OL1             1      -0.241
5       5p_L     1       SOL             OL2             1      -0.241

In ffG53a6.atp 
 5p_O  15.99940 ;     O TIP5P Water
 5p_H   1.00800 ;     H TIP5P Water
 5p_L   0.00000 ;     L TIP5P Water

In ffG53a6nb.itp
 5p_O    8 0.000      0.000     A  2.470013e-03  2.278383e-06
 5p_H    1 0.000      0.000     A           0           0
 5p_L    0 0.000      0.000     D           0           0 

2. Write top file.
#include "ffG53a6.itp"
#include "tip5p_.itp"  

[ system ]
; Name
Protein

[ molecules ]
; Compound        #mols
 SOL           1

3. Built gro

5
    1SOL     OW    1   0.321   1.614   0.603 
    1SOL    HW1    2   0.377   1.643   0.675 
    1SOL    HW2    3   0.258   1.555   0.645 
    1SOL    OL1    4   0.358   1.581   0.554 
    1SOL    OL2    5   0.288   1.669   0.574 
    0.5 0.5 0.5
 4. grompp -f em.mdp

Then the errors came.


*************************************************
Ji Qing
Institute of Chemistry, Chinese Academy of Sciences
Tel: 0086-10-62562894  ，82618423
*************************************************
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