[gmx-users] Invalid order for directive atomtypes for ligands

Qasim Pars qasimpars at gmail.com
Thu Jun 28 22:19:06 CEST 2018

Dear users,

I have a protein bound to two different ligands. LIG1.itp and LIG2.itp
files of both ligands include [ atomtypes ] part. I get "Invalid order for
directive atomtypes" error while running energy minimization step. Do I
have to combine [ atomtypes ] parts of both ligands to get rid of this

Here is top file of the system:

#include "/amber99sb-ildn.ff/forcefield.itp"
#include "Protein_chain_A.itp"
#include "Protein_chain_B.itp"

#include "/amber99sb-ildn.ff/tip3p.itp"
; Position restraint for each water oxygen
[ position_restraints ]
;  i funct       fcx        fcy        fcz
   1    1       1000       1000       1000

#include "/amber99sb-ildn.ff/ions.itp"

#include "LIG1.itp"
#ifdef POSRES
#include "posre_LIG1.itp"

#include "LIG2.itp"
#ifdef POSRES
#include "posre_LIG2.itp"

[ system ]
Protein in water

[ molecules ]
; Compound        #mols
Protein_chain_A     1
Protein_chain_B     1
LIG1                      1
LIG2                      1
SOL                16018

Thanks in advance
Qasim Pars

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