# No default Improper Dih. types

**URL:** <https://gromacs.bioexcel.eu/t/no-default-improper-dih-types/10398>\
**Category:** User discussions\
**Tags:** forcefield, simulation-setup\
**Created:** [October 22, 2024, 5:29pm UTC](https://gromacs.bioexcel.eu/t/no-default-improper-dih-types/10398 "2024-10-22T17:29:08Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![maheshjee2](https://avatars.discourse-cdn.com/v4/letter/m/cab0a1/32.png) [@maheshjee2](https://gromacs.bioexcel.eu/u/maheshjee2)\
**Post date:** [October 22, 2024, 5:29pm UTC](https://gromacs.bioexcel.eu/t/no-default-improper-dih-types/10398/1 "2024-10-22T17:29:08Z")

</div>

GROMACS version:2024.2  
GROMACS modification: Yes/No  
Here post your question

I was using CGENFF to generate parameters for the small molecules using charmm36 force field. But for my current compound, I am getting error like below:

ERROR 1 [file unl.itp, line 148]:  
No default Bond types

ERROR 2 [file unl.itp, line 410]:  
No default U-B types

ERROR 3 [file unl.itp, line 411]:  
No default U-B types

ERROR 4 [file unl.itp, line 470]:  
No default U-B types

ERROR 5 [file unl.itp, line 472]:  
No default U-B types

ERROR 6 [file unl.itp, line 473]:  
No default U-B types

ERROR 7 [file unl.itp, line 474]:  
No default U-B types

ERROR 8 [file unl.itp, line 478]:  
No default U-B types

ERROR 9 [file unl.itp, line 479]:  
No default U-B types

ERROR 10 [file unl.itp, line 492]:  
No default U-B types

ERROR 11 [file unl.itp, line 512]:  
No default U-B types

ERROR 12 [file unl.itp, line 573]:  
No default Proper Dih. types

ERROR 13 [file unl.itp, line 574]:  
No default Proper Dih. types

ERROR 14 [file unl.itp, line 575]:  
No default Proper Dih. types

ERROR 15 [file unl.itp, line 576]:  
No default Proper Dih. types

ERROR 16 [file unl.itp, line 577]:  
No default Proper Dih. types

ERROR 17 [file unl.itp, line 578]:  
No default Proper Dih. types

ERROR 18 [file unl.itp, line 579]:  
No default Proper Dih. types

ERROR 19 [file unl.itp, line 580]:  
No default Proper Dih. types

ERROR 20 [file unl.itp, line 583]:  
No default Proper Dih. types

ERROR 21 [file unl.itp, line 584]:  
No default Proper Dih. types

ERROR 22 [file unl.itp, line 657]:  
No default Proper Dih. types

ERROR 23 [file unl.itp, line 665]:  
No default Proper Dih. types

ERROR 24 [file unl.itp, line 667]:  
No default Proper Dih. types

ERROR 25 [file unl.itp, line 669]:  
No default Proper Dih. types

ERROR 26 [file unl.itp, line 670]:  
No default Proper Dih. types

ERROR 27 [file unl.itp, line 671]:  
No default Proper Dih. types

ERROR 28 [file unl.itp, line 672]:  
No default Proper Dih. types

ERROR 29 [file unl.itp, line 675]:  
No default Proper Dih. types

ERROR 30 [file unl.itp, line 676]:  
No default Proper Dih. types

ERROR 31 [file unl.itp, line 677]:  
No default Proper Dih. types

ERROR 32 [file unl.itp, line 678]:  
No default Proper Dih. types

ERROR 33 [file unl.itp, line 681]:  
No default Proper Dih. types

ERROR 34 [file unl.itp, line 684]:  
No default Proper Dih. types

ERROR 35 [file unl.itp, line 685]:  
No default Proper Dih. types

ERROR 36 [file unl.itp, line 686]:  
No default Proper Dih. types

ERROR 37 [file unl.itp, line 688]:  
No default Proper Dih. types

ERROR 38 [file unl.itp, line 690]:  
No default Proper Dih. types

ERROR 39 [file unl.itp, line 691]:  
No default Proper Dih. types

ERROR 40 [file unl.itp, line 692]:  
No default Proper Dih. types

ERROR 41 [file unl.itp, line 693]:  
No default Proper Dih. types

ERROR 42 [file unl.itp, line 694]:  
No default Proper Dih. types

ERROR 43 [file unl.itp, line 703]:  
No default Proper Dih. types

ERROR 44 [file unl.itp, line 712]:  
No default Proper Dih. types

ERROR 45 [file unl.itp, line 713]:  
No default Proper Dih. types

ERROR 46 [file unl.itp, line 733]:  
No default Proper Dih. types

ERROR 47 [file unl.itp, line 735]:  
No default Proper Dih. types

ERROR 48 [file unl.itp, line 737]:  
No default Proper Dih. types

ERROR 49 [file unl.itp, line 738]:  
No default Proper Dih. types

ERROR 50 [file unl.itp, line 746]:  
No default Improper Dih. types

* * *

Program: gmx grompp, version 2024.2-Homebrew  
Source file: src/gromacs/gmxpreprocess/topio.cpp (line 577)

Fatal error:  
Syntax error - File unl.prm, line 2  
Last line read:  
‘[bondtypes]’  
Invalid order for directive bondtypes

The ipt and prm files creted by CGENFF is as below:

; Created by cgenff\_charmm2gmx.py

[moleculetype]  
; Name nrexcl  
UNL 3

[atoms]  
; nr type resnr residue atom cgnr charge mass typeB chargeB massB  
; residue 1 UNL rtp UNL q qsum  
1 CG2R61 1 UNL C1 1 -0.002 12.011 ;  
2 CG2R61 1 UNL C2 2 -0.109 12.011 ;  
3 CG2R61 1 UNL C3 3 -0.109 12.011 ;  
4 CG2R61 1 UNL C4 4 -0.002 12.011 ;  
5 CG2R61 1 UNL C5 5 -0.109 12.011 ;  
6 CG2R61 1 UNL C6 6 -0.109 12.011 ;  
7 CG321 1 UNL C7 7 -0.003 12.011 ;  
8 OG2D1 1 UNL O1 8 -0.508 15.999 ;  
9 CG2O1 1 UNL C8 9 0.518 12.011 ;  
10 NG2S1 1 UNL N1 10 -0.513 14.007 ;  
11 HGP1 1 UNL H1 11 0.337 1.008 ;  
12 CG321 1 UNL C9 12 -0.206 12.011 ;  
13 NG2R51 1 UNL N2 13 -0.041 14.007 ;  
14 CG2RC0 1 UNL C10 14 0.304 12.011 ;  
15 CG2R61 1 UNL C11 15 -0.243 12.011 ;  
16 CG2R61 1 UNL C12 16 -0.170 12.011 ;  
17 CG2R61 1 UNL C13 17 -0.167 12.011 ;  
18 CG2R61 1 UNL C14 18 -0.252 12.011 ;  
19 CG2R67 1 UNL C15 19 -0.160 12.011 ;  
20 CG2R67 1 UNL C16 20 -0.160 12.011 ;  
21 CG2R61 1 UNL C17 21 -0.252 12.011 ;  
22 CG2R61 1 UNL C18 22 -0.167 12.011 ;  
23 CG2R61 1 UNL C19 23 -0.170 12.011 ;  
24 CG2R61 1 UNL C20 24 -0.243 12.011 ;  
25 CG2RC0 1 UNL C21 25 0.304 12.011 ;  
26 CG321 1 UNL C22 26 -0.007 12.011 ;  
27 NG2S1 1 UNL N3 27 -0.416 14.007 ;  
28 CG2O1 1 UNL C23 28 0.327 12.011 ;  
29 OG2D1 1 UNL O2 29 -0.464 15.999 ;  
30 HGP1 1 UNL H2 30 0.313 1.008 ;  
31 CG2R61 1 UNL C24 31 -0.173 12.011 ;  
32 CG2R61 1 UNL C25 32 -0.272 12.011 ;  
33 CG2R61 1 UNL C26 33 -0.425 12.011 ;  
34 CG2RC0 1 UNL C27 34 0.362 12.011 ;  
35 CG2R53 1 UNL C28 35 0.366 12.011 ;  
36 OG2D1 1 UNL O3 36 -0.524 15.999 ;  
37 NG2R53 1 UNL N4 37 -0.266 14.007 ;  
38 CG3C52 1 UNL C29 38 0.454 12.011 ;  
39 CG2RC0 1 UNL C30 39 -0.103 12.011 ;  
40 CG2R61 1 UNL C31 40 -0.217 12.011 ;  
41 CG311 1 UNL C32 41 0.084 12.011 ;  
42 CG321 1 UNL C33 42 -0.149 12.011 ;  
43 CG321 1 UNL C34 43 -0.207 12.011 ;  
44 CG2O1 1 UNL C35 44 0.521 12.011 ;  
45 OG2D1 1 UNL O4 45 -0.490 15.999 ;  
46 NG2S1 1 UNL N5 46 -0.465 14.007 ;  
47 CG2O1 1 UNL C36 47 0.528 12.011 ;  
48 OG2D1 1 UNL O5 48 -0.486 15.999 ;  
49 HGP1 1 UNL H3 49 0.345 1.008 ;  
50 HGR61 1 UNL H4 50 0.115 1.008 ;  
51 HGR61 1 UNL H5 51 0.115 1.008 ;  
52 HGR61 1 UNL H6 52 0.115 1.008 ;  
53 HGR61 1 UNL H7 53 0.115 1.008 ;  
54 HGA2 1 UNL H8 54 0.090 1.008 ;  
55 HGA2 1 UNL H9 55 0.090 1.008 ;  
56 HGA2 1 UNL H10 56 0.090 1.008 ;  
57 HGA2 1 UNL H11 57 0.090 1.008 ;  
58 HGR61 1 UNL H12 58 0.194 1.008 ;  
59 HGR61 1 UNL H13 59 0.127 1.008 ;  
60 HGR61 1 UNL H14 60 0.115 1.008 ;  
61 HGR61 1 UNL H15 61 0.275 1.008 ;  
62 HGR61 1 UNL H16 62 0.275 1.008 ;  
63 HGR61 1 UNL H17 63 0.115 1.008 ;  
64 HGR61 1 UNL H18 64 0.127 1.008 ;  
65 HGR61 1 UNL H19 65 0.194 1.008 ;  
66 HGA2 1 UNL H20 66 0.090 1.008 ;  
67 HGA2 1 UNL H21 67 0.090 1.008 ;  
68 HGR61 1 UNL H22 68 0.127 1.008 ;  
69 HGR61 1 UNL H23 69 0.300 1.008 ;  
70 HGA2 1 UNL H24 70 0.090 1.008 ;  
71 HGA2 1 UNL H25 71 0.090 1.008 ;  
72 HGR61 1 UNL H26 72 0.117 1.008 ;  
73 HGA1 1 UNL H27 73 0.090 1.008 ;  
74 HGA2 1 UNL H28 74 0.090 1.008 ;  
75 HGA2 1 UNL H29 75 0.090 1.008 ;  
76 HGA2 1 UNL H30 76 0.090 1.008 ;  
77 HGA2 1 UNL H31 77 0.090 1.008 ;

[bonds]  
; ai aj funct c0 c1 c2 c3  
1 7 1  
1 2 1  
1 6 1  
2 3 1  
2 50 1  
3 4 1  
3 51 1  
4 5 1  
4 26 1  
5 6 1  
5 52 1  
6 53 1  
7 10 1  
7 54 1  
7 55 1  
8 9 1  
9 12 1  
9 10 1  
10 11 1  
12 13 1  
12 56 1  
12 57 1  
13 14 1  
13 25 1  
14 15 1  
14 19 1  
15 16 1  
15 58 1  
16 17 1  
16 59 1  
17 18 1  
17 60 1  
18 19 1  
18 61 1  
19 20 1  
20 21 1  
20 25 1  
21 22 1  
21 62 1  
22 23 1  
22 63 1  
23 24 1  
23 64 1  
24 25 1  
24 65 1  
26 27 1  
26 66 1  
26 67 1  
27 28 1  
27 30 1  
28 29 1  
28 31 1  
31 32 1  
31 40 1  
32 33 1  
32 68 1  
33 34 1  
33 69 1  
34 35 1  
34 39 1  
35 36 1  
35 37 1  
37 38 1  
37 41 1  
38 39 1  
38 70 1  
38 71 1  
39 40 1  
40 72 1  
41 42 1  
41 47 1  
41 73 1  
42 43 1  
42 74 1  
42 75 1  
43 44 1  
43 76 1  
43 77 1  
44 45 1  
44 46 1  
46 47 1  
46 49 1  
47 48 1

[pairs]  
; ai aj funct c0 c1 c2 c3  
1 4 1  
1 51 1  
1 52 1  
1 9 1  
1 11 1  
2 10 1  
2 54 1  
2 55 1  
2 5 1  
2 53 1  
2 26 1  
3 7 1  
3 6 1  
3 52 1  
3 27 1  
3 66 1  
3 67 1  
4 50 1  
4 53 1  
4 28 1  
4 30 1  
5 7 1  
5 51 1  
5 27 1  
5 66 1  
5 67 1  
6 10 1  
6 54 1  
6 55 1  
6 50 1  
6 26 1  
7 50 1  
7 53 1  
7 8 1  
7 12 1  
8 13 1  
8 56 1  
8 57 1  
8 11 1  
9 54 1  
9 55 1  
9 14 1  
9 25 1  
10 13 1  
10 56 1  
10 57 1  
11 54 1  
11 55 1  
11 12 1  
12 15 1  
12 19 1  
12 20 1  
12 24 1  
13 16 1  
13 58 1  
13 18 1  
13 21 1  
13 23 1  
13 65 1  
14 56 1  
14 57 1  
14 24 1  
14 17 1  
14 59 1  
14 61 1  
14 21 1  
15 25 1  
15 18 1  
15 20 1  
15 60 1  
16 19 1  
16 61 1  
17 58 1  
17 20 1  
18 59 1  
18 21 1  
18 25 1  
19 58 1  
19 60 1  
19 22 1  
19 62 1  
19 24 1  
20 61 1  
20 23 1  
20 63 1  
20 65 1  
21 24 1  
21 64 1  
22 25 1  
22 65 1  
23 62 1  
24 63 1  
25 56 1  
25 57 1  
25 62 1  
25 64 1  
26 51 1  
26 52 1  
26 29 1  
26 31 1  
27 32 1  
27 40 1  
28 66 1  
28 67 1  
28 33 1  
28 68 1  
28 39 1  
28 72 1  
29 30 1  
29 32 1  
29 40 1  
30 66 1  
30 67 1  
30 31 1  
31 34 1  
31 69 1  
31 38 1  
32 39 1  
32 72 1  
32 35 1  
33 40 1  
33 36 1  
33 37 1  
33 38 1  
34 68 1  
34 41 1  
34 70 1  
34 71 1  
34 72 1  
35 69 1  
35 40 1  
35 70 1  
35 71 1  
35 42 1  
35 47 1  
35 73 1  
36 39 1  
36 38 1  
36 41 1  
37 40 1  
37 43 1  
37 74 1  
37 75 1  
37 46 1  
37 48 1  
38 42 1  
38 47 1  
38 73 1  
38 72 1  
39 69 1  
39 41 1  
40 68 1  
40 70 1  
40 71 1  
41 70 1  
41 71 1  
41 44 1  
41 76 1  
41 77 1  
41 49 1  
42 46 1  
42 48 1  
42 45 1  
43 47 1  
43 73 1  
43 49 1  
44 74 1  
44 75 1  
44 48 1  
45 76 1  
45 77 1  
45 47 1  
45 49 1  
46 73 1  
46 76 1  
46 77 1  
47 74 1  
47 75 1  
48 73 1  
48 49 1  
50 51 1  
52 53 1  
58 59 1  
59 60 1  
60 61 1  
62 63 1  
63 64 1  
64 65 1  
68 69 1  
73 74 1  
73 75 1  
74 76 1  
74 77 1  
75 76 1  
75 77 1

[angles]  
; ai aj ak funct c0 c1 c2 c3  
7 1 2 5  
7 1 6 5  
2 1 6 5  
1 2 3 5  
1 2 50 5  
3 2 50 5  
2 3 4 5  
2 3 51 5  
4 3 51 5  
3 4 5 5  
3 4 26 5  
5 4 26 5  
4 5 6 5  
4 5 52 5  
6 5 52 5  
1 6 5 5  
1 6 53 5  
5 6 53 5  
1 7 10 5  
1 7 54 5  
1 7 55 5  
10 7 54 5  
10 7 55 5  
54 7 55 5  
8 9 12 5  
8 9 10 5  
12 9 10 5  
7 10 9 5  
7 10 11 5  
9 10 11 5  
9 12 13 5  
9 12 56 5  
9 12 57 5  
13 12 56 5  
13 12 57 5  
56 12 57 5  
12 13 14 5  
12 13 25 5  
14 13 25 5  
13 14 15 5  
13 14 19 5  
15 14 19 5  
14 15 16 5  
14 15 58 5  
16 15 58 5  
15 16 17 5  
15 16 59 5  
17 16 59 5  
16 17 18 5  
16 17 60 5  
18 17 60 5  
17 18 19 5  
17 18 61 5  
19 18 61 5  
14 19 18 5  
14 19 20 5  
18 19 20 5  
19 20 21 5  
19 20 25 5  
21 20 25 5  
20 21 22 5  
20 21 62 5  
22 21 62 5  
21 22 23 5  
21 22 63 5  
23 22 63 5  
22 23 24 5  
22 23 64 5  
24 23 64 5  
23 24 25 5  
23 24 65 5  
25 24 65 5  
13 25 20 5  
13 25 24 5  
20 25 24 5  
4 26 27 5  
4 26 66 5  
4 26 67 5  
27 26 66 5  
27 26 67 5  
66 26 67 5  
26 27 28 5  
26 27 30 5  
28 27 30 5  
27 28 29 5  
27 28 31 5  
29 28 31 5  
28 31 32 5  
28 31 40 5  
32 31 40 5  
31 32 33 5  
31 32 68 5  
33 32 68 5  
32 33 34 5  
32 33 69 5  
34 33 69 5  
33 34 35 5  
33 34 39 5  
35 34 39 5  
34 35 36 5  
34 35 37 5  
36 35 37 5  
35 37 38 5  
35 37 41 5  
38 37 41 5  
37 38 39 5  
37 38 70 5  
37 38 71 5  
39 38 70 5  
39 38 71 5  
70 38 71 5  
34 39 38 5  
34 39 40 5  
38 39 40 5  
31 40 39 5  
31 40 72 5  
39 40 72 5  
37 41 42 5  
37 41 47 5  
37 41 73 5  
42 41 47 5  
42 41 73 5  
47 41 73 5  
41 42 43 5  
41 42 74 5  
41 42 75 5  
43 42 74 5  
43 42 75 5  
74 42 75 5  
42 43 44 5  
42 43 76 5  
42 43 77 5  
44 43 76 5  
44 43 77 5  
76 43 77 5  
43 44 45 5  
43 44 46 5  
45 44 46 5  
44 46 47 5  
44 46 49 5  
47 46 49 5  
41 47 46 5  
41 47 48 5  
46 47 48 5

[dihedrals]  
; ai aj ak al funct c0 c1 c2 c3 c4 c5  
2 1 7 10 9  
2 1 7 54 9  
2 1 7 55 9  
6 1 7 10 9  
6 1 7 54 9  
6 1 7 55 9  
7 1 2 3 9  
7 1 2 50 9  
6 1 2 3 9  
6 1 2 50 9  
7 1 6 5 9  
7 1 6 53 9  
2 1 6 5 9  
2 1 6 53 9  
1 2 3 4 9  
1 2 3 51 9  
50 2 3 4 9  
50 2 3 51 9  
2 3 4 5 9  
2 3 4 26 9  
51 3 4 5 9  
51 3 4 26 9  
3 4 5 6 9  
3 4 5 52 9  
26 4 5 6 9  
26 4 5 52 9  
3 4 26 27 9  
3 4 26 66 9  
3 4 26 67 9  
5 4 26 27 9  
5 4 26 66 9  
5 4 26 67 9  
4 5 6 1 9  
4 5 6 53 9  
52 5 6 1 9  
52 5 6 53 9  
1 7 10 9 9  
1 7 10 11 9  
54 7 10 9 9  
54 7 10 11 9  
55 7 10 9 9  
55 7 10 11 9  
8 9 12 13 9  
8 9 12 56 9  
8 9 12 57 9  
10 9 12 13 9  
10 9 12 56 9  
10 9 12 57 9  
8 9 10 7 9  
8 9 10 11 9  
12 9 10 7 9  
12 9 10 11 9  
9 12 13 14 9  
9 12 13 25 9  
56 12 13 14 9  
56 12 13 25 9  
57 12 13 14 9  
57 12 13 25 9  
12 13 14 15 9  
12 13 14 19 9  
25 13 14 15 9  
25 13 14 19 9  
12 13 25 20 9  
12 13 25 24 9  
14 13 25 20 9  
14 13 25 24 9  
13 14 15 16 9  
13 14 15 58 9  
19 14 15 16 9  
19 14 15 58 9  
13 14 19 18 9  
13 14 19 20 9  
15 14 19 18 9  
15 14 19 20 9  
14 15 16 17 9  
14 15 16 59 9  
58 15 16 17 9  
58 15 16 59 9  
15 16 17 18 9  
15 16 17 60 9  
59 16 17 18 9  
59 16 17 60 9  
16 17 18 19 9  
16 17 18 61 9  
60 17 18 19 9  
60 17 18 61 9  
17 18 19 14 9  
17 18 19 20 9  
61 18 19 14 9  
61 18 19 20 9  
14 19 20 21 9  
14 19 20 25 9  
18 19 20 21 9  
18 19 20 25 9  
19 20 21 22 9  
19 20 21 62 9  
25 20 21 22 9  
25 20 21 62 9  
19 20 25 13 9  
19 20 25 24 9  
21 20 25 13 9  
21 20 25 24 9  
20 21 22 23 9  
20 21 22 63 9  
62 21 22 23 9  
62 21 22 63 9  
21 22 23 24 9  
21 22 23 64 9  
63 22 23 24 9  
63 22 23 64 9  
22 23 24 25 9  
22 23 24 65 9  
64 23 24 25 9  
64 23 24 65 9  
23 24 25 13 9  
23 24 25 20 9  
65 24 25 13 9  
65 24 25 20 9  
4 26 27 28 9  
4 26 27 30 9  
66 26 27 28 9  
66 26 27 30 9  
67 26 27 28 9  
67 26 27 30 9  
26 27 28 29 9  
26 27 28 31 9  
30 27 28 29 9  
30 27 28 31 9  
27 28 31 32 9  
27 28 31 40 9  
29 28 31 32 9  
29 28 31 40 9  
28 31 32 33 9  
28 31 32 68 9  
40 31 32 33 9  
40 31 32 68 9  
28 31 40 39 9  
28 31 40 72 9  
32 31 40 39 9  
32 31 40 72 9  
31 32 33 34 9  
31 32 33 69 9  
68 32 33 34 9  
68 32 33 69 9  
32 33 34 35 9  
32 33 34 39 9  
69 33 34 35 9  
69 33 34 39 9  
33 34 35 36 9  
33 34 35 37 9  
39 34 35 36 9  
39 34 35 37 9  
33 34 39 38 9  
33 34 39 40 9  
35 34 39 38 9  
35 34 39 40 9  
34 35 37 38 9  
34 35 37 41 9  
36 35 37 38 9  
36 35 37 41 9  
35 37 38 39 9  
35 37 38 70 9  
35 37 38 71 9  
41 37 38 39 9  
41 37 38 70 9  
41 37 38 71 9  
35 37 41 42 9  
35 37 41 47 9  
35 37 41 73 9  
38 37 41 42 9  
38 37 41 47 9  
38 37 41 73 9  
37 38 39 34 9  
37 38 39 40 9  
70 38 39 34 9  
70 38 39 40 9  
71 38 39 34 9  
71 38 39 40 9  
34 39 40 31 9  
34 39 40 72 9  
38 39 40 31 9  
38 39 40 72 9  
37 41 42 43 9  
37 41 42 74 9  
37 41 42 75 9  
47 41 42 43 9  
47 41 42 74 9  
47 41 42 75 9  
73 41 42 43 9  
73 41 42 74 9  
73 41 42 75 9  
37 41 47 46 9  
37 41 47 48 9  
42 41 47 46 9  
42 41 47 48 9  
73 41 47 46 9  
73 41 47 48 9  
41 42 43 44 9  
41 42 43 76 9  
41 42 43 77 9  
74 42 43 44 9  
74 42 43 76 9  
74 42 43 77 9  
75 42 43 44 9  
75 42 43 76 9  
75 42 43 77 9  
42 43 44 45 9  
42 43 44 46 9  
76 43 44 45 9  
76 43 44 46 9  
77 43 44 45 9  
77 43 44 46 9  
43 44 46 47 9  
43 44 46 49 9  
45 44 46 47 9  
45 44 46 49 9  
44 46 47 41 9  
44 46 47 48 9  
49 46 47 41 9  
49 46 47 48 9

[dihedrals]  
; ai aj ak al funct c0 c1 c2 c3  
9 12 10 8 2  
28 31 27 29 2  
35 34 37 36 2  
44 43 46 45 2  
47 41 46 48 2

…

[bondtypes]  
; i j func b0 kb  
CG2R53 CG2RC0 1 0.14200000 301248.00

[angletypes]  
; i j k func theta0 ktheta ub0 kub  
CG2RC0 CG2R53 NG2R53 5 108.500000 460.240000 0.00000000 0.00  
CG2RC0 CG2R53 OG2D1 5 127.500000 508.774400 0.00000000 0.00  
CG2R53 CG2RC0 CG2R61 5 134.100000 502.080000 0.00000000 0.00  
CG2R53 CG2RC0 CG2RC0 5 105.900000 753.120000 0.00000000 0.00  
CG2O1 CG311 NG2R53 5 107.000000 418.400000 0.00000000 0.00  
CG2RC0 CG3C52 NG2R53 5 111.600000 878.640000 0.00000000 0.00  
CG2RC0 NG2R51 CG321 5 125.900000 585.760000 0.00000000 0.00  
CG311 NG2R53 CG3C52 5 116.000000 317.984000 0.00000000 0.00  
CG2O1 NG2S1 CG2O1 5 124.600000 391.622400 0.00000000 0.00

[dihedraltypes]  
; i j k l func phi0 kphi mult  
NG2S1 CG2O1 CG311 NG2R53 9 0.000000 2.510400 1  
OG2D1 CG2O1 CG311 NG2R53 9 0.000000 0.000000 1  
CG311 CG2O1 NG2S1 CG2O1 9 180.000000 3.096160 2  
CG321 CG2O1 NG2S1 CG2O1 9 180.000000 6.903600 2  
OG2D1 CG2O1 NG2S1 CG2O1 9 180.000000 2.426720 2  
NG2R53 CG2R53 CG2RC0 CG2R61 9 180.000000 6.276000 2  
NG2R53 CG2R53 CG2RC0 CG2RC0 9 180.000000 37.656000 2  
OG2D1 CG2R53 CG2RC0 CG2R61 9 180.000000 5.020800 2  
OG2D1 CG2R53 CG2RC0 CG2RC0 9 180.000000 5.020800 2  
CG2RC0 CG2R53 NG2R53 CG311 9 0.000000 6.694400 1  
CG2RC0 CG2R53 NG2R53 CG311 9 180.000000 10.460000 2  
CG2RC0 CG2R53 NG2R53 CG3C52 9 0.000000 6.694400 1  
CG2RC0 CG2R53 NG2R53 CG3C52 9 180.000000 10.460000 2  
CG2O1 CG2R61 CG2R61 CG2RC0 9 180.000000 12.970400 2  
CG2R61 CG2R61 CG2RC0 CG2R53 9 180.000000 6.276000 2  
HGR61 CG2R61 CG2RC0 CG2R53 9 180.000000 0.000000 2  
CG2R53 CG2RC0 CG2RC0 CG2R61 9 180.000000 6.276000 2  
CG2R53 CG2RC0 CG2RC0 CG3C52 9 180.000000 20.920000 2  
CG2R61 CG2RC0 CG3C52 NG2R53 9 0.000000 3.765600 3  
CG2RC0 CG2RC0 CG3C52 NG2R53 9 180.000000 4.184000 3  
CG2R61 CG2RC0 NG2R51 CG321 9 180.000000 0.047698 2  
CG2R67 CG2RC0 NG2R51 CG321 9 180.000000 46.024000 2  
NG2R53 CG311 CG321 CG321 9 0.000000 0.836800 3  
CG2O1 CG311 NG2R53 CG2R53 9 180.000000 0.000000 1  
CG2O1 CG311 NG2R53 CG3C52 9 0.000000 6.473066 1  
CG2O1 CG311 NG2R53 CG3C52 9 180.000000 4.879381 2  
CG321 CG311 NG2R53 CG3C52 9 0.000000 12.808061 1  
CG321 CG311 NG2R53 CG3C52 9 180.000000 0.467771 2  
HGA1 CG311 NG2R53 CG3C52 9 0.000000 1.757280 3  
CG2O1 CG321 NG2R51 CG2RC0 9 180.000000 3.743425 1  
CG2O1 CG321 NG2R51 CG2RC0 9 180.000000 1.776526 2  
CG2O1 CG321 NG2R51 CG2RC0 9 0.000000 2.025893 3  
HGA2 CG321 NG2R51 CG2RC0 9 0.000000 0.000000 3  
CG2RC0 CG3C52 NG2R53 CG2R53 9 180.000000 9.665040 3  
CG2RC0 CG3C52 NG2R53 CG311 9 180.000000 9.665040 3  
HGA2 CG3C52 NG2R53 CG311 9 0.000000 0.000000 3

[dihedraltypes]  
; ‘improper’ dihedrals  
; i j k l func phi0 kphi  
CG2R53 CG2RC0 NG2R53 OG2D1 2 0.000000 753.120000

If you can help to fix this, I would appreciate it very much.

Thank you!

Mahesh

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<div class="post-metadata">

**Author:** ![MagnusL](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/magnusl/32/2380_2.png) [@MagnusL](https://gromacs.bioexcel.eu/u/MagnusL)\
**Post date:** [October 23, 2024, 4:17am UTC](https://gromacs.bioexcel.eu/t/no-default-improper-dih-types/10398/2 "2024-10-23T04:17:29Z")

</div>

All `[<bond,angle,dihedral,...>types]` sections must come before the first `[molecule types]` section, see [Common errors when using GROMACS - GROMACS 2024.3 documentation](https://manual.gromacs.org/current/user-guide/run-time-errors.html#invalid-order-for-directive-xxx).

The other errors you are getting before is because of the same error, i.e., the parameters of bonded interactions are not defined when you use them. Move bonded and non-bonded `[...types]` sections to a separate file and include that after the `forcefield.itp` in your topology file.

---

<div class="post-metadata">

**Author:** ![maheshjee2](https://avatars.discourse-cdn.com/v4/letter/m/cab0a1/32.png) [@maheshjee2](https://gromacs.bioexcel.eu/u/maheshjee2)\
**Post date:** [October 23, 2024, 11:47pm UTC](https://gromacs.bioexcel.eu/t/no-default-improper-dih-types/10398/3 "2024-10-23T23:47:20Z")

</div>

Thank you. But I am still getting this error: ERROR 1 [file unl.itp, line 7]:  
Atoms in the .top are not numbered consecutively from 1 (rather, atomnr =  
1, while at-\>nr = 1371)

Can you please help?

Mahesh

---

<div class="post-metadata">

**Author:** ![MagnusL](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/magnusl/32/2380_2.png) [@MagnusL](https://gromacs.bioexcel.eu/u/MagnusL)\
**Post date:** [October 24, 2024, 8:39am UTC](https://gromacs.bioexcel.eu/t/no-default-improper-dih-types/10398/4 "2024-10-24T08:39:31Z")

</div>

Have you looked at the atom numbering in the itp file?