[gmx-users] Invalid order for directive bondtypes

[Atila Petrosian]

Dear gromacs users

I want to do MD simulation of a CNT.

I used aromatic carbon from charmm.ff

I created a cnt.ff folder containing following files:

ffcnt.atp:
-----------
CA    12.01100 ;    aromatic C
-------------------------------------------------------------------------
ffcnt.n2t:
-----------
C    CA    0.00     12.011    3    C 0.141   C 0.141   C 0.141
C    CA    0.00     12.011    2    C 0.141   C 0.141
-------------------------------------------------------------------------
ffcntbonded.itp:
--------------------
[ bondtypes ]
; i      j       func       b0      kb
CA      CA        1        0.1375   0.0

[ angletypes ]
; i      j      k      func      th0      cth       ub0      cub
CA      CA      CA       5       120.00   0.0     0.24162  29288.0

[ dihedraltypes ]
; i      j      k       l      func    phi0    cp      mult
CA      CA      CA      CA      9       180.00  0.0     2
-------------------------------------------------------------------------
ffcntnonbonded.itp:
-------------------------
[ atomtypes
]
;name    at.num    mass    charge    ptype    sigma
epsi
CA       6        12.01100        0.00    A       0.335
0.234463
-------------------------------------------------------------------------
ffcnt.rtp:
----------
[ bondedtypes
]
; Col 1: Type of
bond
; Col 2: Type of
angles
; Col 3: Type of proper
dihedrals
; Col 4: Type of improper
dihedrals
; Col 5: Generate all dihedrals if 1, only heavy atoms of
0.
; Col 6: Number of excluded neighbors for nonbonded
interactions
; Col 7: Generate 1,4 interactions between pairs of hydrogens if
1
; Col 8: Remove propers over the same bond as an improper if it is
1
; bonds  angles  dihedrals  impropers all_dihedrals nrexcl HH14
RemoveDih
     1       5          9        2        1           3      1
0


[ ALA
]
 [ atoms
]
    N    NH1    -0.47
0
    HN    H    0.31
1
    CA    CT1    0.07
2
    HA    HB    0.09
3
    CB    CT3    -0.27
4
    HB1    HA    0.09
5
    HB2    HA    0.09
6
    HB3    HA    0.09
7
    C    C    0.51
8
    O    O    -0.51
9
.
.
.
-------------------------------------------------------------------------
forcefield.itp:
----------------
#define _FF_CNT

[ defaults ]
; nbfunc    comb-rule    gen-pairs    fudgeLJ    fudgeQQ
    1           2          yes           1.0    1.0

#include "ffcntbonded.itp"
#include "ffcntnonbonded.itp"
-------------------------------------------------------------------------

After creating cnt.top file using g_x2top, I used grompp for energy
minimization, but I encountered with Fatal Error:

Syntax error - File ffcntbonded.itp, line 1
Last line read:
'[ bondtypes ]'
Invalid order for directive bondtypes

Before doing MD simulation, I checked carbon nanotube in the GROMACS
website:

http://www.gromacs.org/Documentation/How-tos/Carbon_Nanotube?highlight=nanotube

In my opinion, my manner is true.

How to solve this problem?

Any help will highly appreciated.