[gmx-users] How to add two different "defaults" parameters in topology file

[mbhendle]

Hello all, 

I am trying to simulate polymers in tip4p-ice and for that I need to set
two different "defaults" parameters for polymer chain and TIP4P-ICE in
topology file. The "moleculetype" for Polymer chain and water is also
different: 

[ defaults]
; nbfunc comb-rule gen-pairs fudgeLJ fudgeQQ    (for polymer)
1                  3             yes        0.5         0.5 

[ defaults]
; nbfunc comb-rule gen-pairs fudgeLJ fudgeQQ    (for TIP4P-ICE)
1                  2             no          1             1 

[moleculetype] 

;Name     nrexcl 

Other       3  ;(Polymer) 

SOL          1  ;(TIP4P-ICE)  

For this purpose, I have created two different ".itp" files for polymer
chain and TIP4P-ICE. But while running "gmx grompp" gromacs is showing
"Invalid order for directive moleculetype". I also tried putting two
defaults parameters into ".top" file itself. But it also showed error. 

Please suggest how to do it. 

Thanks & Regards, 

Mangesh Bhendale