[gmx-users] Atomtype opls_236 not found

[Anjali Patel]

Hello users,

I know there are lots of discussion on this topic and i have gone through
all those even whole chapter 5 also. but didn’t get any solution or where i
am wrong. i want to generate .tpr file. i am using gmx grompp -f ions.mdp
-c solv.gro -p topol.top -o ions.tpr. in that i have generated CNT topology
file by this http://chembytes.wikidot.com/grocnt and molecule topology file
taken by Automated topology builder (ATB) now i have merged both file and
.top files is here,

; Include forcefield parameters
#include "./cnt.ff/forcefield.itp"

[ moleculetype ]
; Name            nrexcl
CNT                 3
[ atoms ]
;   nr       type  resnr residue  atom   cgnr     charge       mass
typeB    chargeB      massB
     1         CJ      1    UNK     C1      1          0     12.011   ;
qtot 0
     2         CJ      1    UNK     C2      2          0     12.011   ;
qtot 0
     3         CJ      1    UNK     C3      3          0     12.011   ;
qtot 0
     4         CJ      1    UNK     C4      4          0     12.011   ;
qtot 0
  .......

#ifdef POSRES_WATER
; Position restraint for each water oxygen
[ position_restraints ]
;  i funct       fcx        fcy        fcz
   1    1       1000       1000       1000
#endif

; Include forcefield parameters
#include "./oplsaa.ff/forcefield.itp"

; Include ligand topology
#include "drug.itp"

; Include topology for ions
#include "./oplsaa.ff/spc.itp"

; Include water topology
#include "oplsaa.ff/tip3p.itp"

[ system ]
; Name
CNT in water

[ molecules ]
; Compound        #mols
CNT               1
_JDN               1
SOL              2515

where drug.itp is below


; Include forcefield parameters
#include "./oplsaa.ff/forcefield.itp"

[ moleculetype ]
; Name            nrexcl
_JDN                3

[ atoms ]
;   nr       type  resnr residue  atom   cgnr     charge       mass
typeB    chargeB      massB
     1   opls_236      0   _JDN    O14      0     -0.500
15.99940
     2   opls_145      0   _JDN    C41      1      0.000
12.01100
     3   opls_145      0   _JDN    C42      2      0.000
12.01100
     4   opls_145      0   _JDN    C47      3     -0.115
12.01100
     5   opls_146      0   _JDN    H51      3      0.115
1.00800
............

opls_236 and all atom types are already in .rtp, .atp and ffnonbonded.itp
file. i am not getting the issue. as it is very urgent for me

Thanks in advance for any advice and suggestions

With regards
Anjali Patel
Research Scholar
Department of Physics
The M S University of Baroda, Vadodara-390002