# Ligand LINCS error Help

**URL:** <https://gromacs.bioexcel.eu/t/ligand-lincs-error-help/4975>\
**Category:** User discussions\
**Created:** [October 7, 2022, 1:23am UTC](https://gromacs.bioexcel.eu/t/ligand-lincs-error-help/4975 "2022-10-07T01:23:10Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![mike](https://avatars.discourse-cdn.com/v4/letter/m/58f4c7/32.png) [@mike](https://gromacs.bioexcel.eu/u/mike)\
**Post date:** [October 7, 2022, 1:23am UTC](https://gromacs.bioexcel.eu/t/ligand-lincs-error-help/4975/1 "2022-10-07T01:23:10Z")

</div>

GROMACS version: latest  
GROMACS modification: Yes  
Here post your question

Below are my topology file and a bit of the errors I am receiving.  
I have performed a protein-ligand simulation. I received many LINCS errors. When I perform just the protein, the simulation works. Now I tried just doing the ligand, and as suspected, the ligand is giving many LINCS warnings. The LINCS warnings has to do with the angles, how do I fix it? The Lincs warnings are the following:

Step 215, time 0.43 (ps) LINCS WARNING  
relative constraint deviation after LINCS:  
rms 0.848962, max 2.546885 (between atoms 11 and 10)  
bonds that rotated more than 30 degrees:  
atom 1 atom 2 angle previous, current, constraint length  
11 10 90.0 0.1103 0.3352 0.0945  
11 10 90.0 0.1103 0.3352 0.0945  
11 10 90.0 0.1103 0.3352 0.0945  
11 10 90.0 0.1103 0.3352 0.0945  
Wrote pdb files with previous and current coordinates

Step 216, time 0.432 (ps) LINCS WARNING  
relative constraint deviation after LINCS:  
rms 0.075398, max 0.226194 (between atoms 11 and 10)  
bonds that rotated more than 30 degrees:  
atom 1 atom 2 angle previous, current, constraint length  
11 10 90.0 0.3352 0.1159 0.0945  
11 10 90.0 0.3352 0.1159 0.0945  
11 10 90.0 0.3352 0.1159 0.0945  
11 10 90.0 0.3352 0.1159 0.0945

Step 217, time 0.434 (ps) LINCS WARNING  
relative constraint deviation after LINCS:  
rms 0.849561, max 2.548684 (between atoms 11 and 10)  
bonds that rotated more than 30 degrees:  
atom 1 atom 2 angle previous, current, constraint length  
11 10 90.0 0.1159 0.3354 0.0945  
11 10 90.0 0.1159 0.3354 0.0945  
11 10 90.0 0.1159 0.3354 0.0945  
11 10 90.0 0.1159 0.3354 0.0945  
Wrote pdb files with previous and current coordinates

Step 218, time 0.436 (ps) LINCS WARNING  
relative constraint deviation after LINCS:  
rms 0.080784, max 0.242351 (between atoms 11 and 10)  
bonds that rotated more than 30 degrees:  
atom 1 atom 2 angle previous, current, constraint length  
11 10 90.0 0.3354 0.1174 0.0945  
11 10 90.0 0.3354 0.1174 0.0945  
11 10 90.0 0.3354 0.1174 0.0945  
11 10 90.0 0.3354 0.1174 0.0945

Step 219, time 0.438 (ps) LINCS WARNING  
relative constraint deviation after LINCS:  
rms 0.859736, max 2.579207 (between atoms 11 and 10)  
bonds that rotated more than 30 degrees:  
atom 1 atom 2 angle previous, current, constraint length  
6 5 41.8 0.0945 0.0945 0.0945  
6 5 41.8 0.0945 0.0945 0.0945  
6 5 41.8 0.0945 0.0945 0.0945  
6 5 41.8 0.0945 0.0945 0.0945  
11 10 90.0 0.1174 0.3382 0.0945  
11 10 90.0 0.1174 0.3382 0.0945  
11 10 90.0 0.1174 0.3382 0.0945  
11 10 90.0 0.1174 0.3382 0.0945  
16 15 30.3 0.0945 0.0945 0.0945  
16 15 30.3 0.0945 0.0945 0.0945  
16 15 30.3 0.0945 0.0945 0.0945  
16 15 30.3 0.0945 0.0945 0.0945

Here below is my topolgy file

;  
; GENERATED BY LigParGen Server  
; Jorgensen Lab @ Yale University  
;  
[atomtypes]  
opls\_808 O808 15.9990 0.000 A 2.96000E-01 8.78640E-01  
opls\_823 N823 14.0070 0.000 A 3.25000E-01 7.11280E-01  
opls\_825 N825 14.0070 0.000 A 3.25000E-01 7.11280E-01  
opls\_832 H832 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_806 O806 15.9990 0.000 A 2.90000E-01 5.85760E-01  
opls\_840 H840 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_828 C828 12.0110 0.000 A 3.50000E-01 3.34720E-01  
opls\_815 H815 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_812 P812 30.9738 0.000 A 3.74000E-01 8.36800E-01  
opls\_824 C824 12.0110 0.000 A 3.30000E-01 2.76144E-01  
opls\_834 N834 14.0070 0.000 A 3.25000E-01 7.11280E-01  
opls\_814 O814 15.9990 0.000 A 3.12000E-01 7.11280E-01  
opls\_818 C818 12.0110 0.000 A 3.55000E-01 2.92880E-01  
opls\_821 C821 12.0110 0.000 A 3.55000E-01 2.92880E-01  
opls\_829 O829 15.9990 0.000 A 2.96000E-01 8.78640E-01  
opls\_819 O819 15.9990 0.000 A 2.90000E-01 5.85760E-01  
opls\_827 C827 12.0110 0.000 A 3.55000E-01 2.92880E-01  
opls\_801 O801 15.9990 0.000 A 2.96000E-01 8.78640E-01  
opls\_800 P800 30.9738 0.000 A 3.74000E-01 8.36800E-01  
opls\_831 C831 12.0110 0.000 A 3.55000E-01 3.17984E-01  
opls\_817 C817 12.0110 0.000 A 3.30000E-01 2.76144E-01  
opls\_837 O837 15.9990 0.000 A 3.12000E-01 7.11280E-01  
opls\_839 O839 15.9990 0.000 A 3.12000E-01 7.11280E-01  
opls\_833 N833 14.0070 0.000 A 3.25000E-01 7.11280E-01  
opls\_835 H835 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_816 O816 15.9990 0.000 A 2.90000E-01 5.85760E-01  
opls\_836 H836 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_803 H803 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_813 O813 15.9990 0.000 A 2.96000E-01 8.78640E-01  
opls\_804 O804 15.9990 0.000 A 3.12000E-01 7.11280E-01  
opls\_810 H810 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_807 P807 30.9738 0.000 A 3.74000E-01 8.36800E-01  
opls\_826 C826 12.0110 0.000 A 3.55000E-01 2.92880E-01  
opls\_830 N830 14.0070 0.000 A 3.25000E-01 7.11280E-01  
opls\_811 O811 15.9990 0.000 A 2.90000E-01 5.85760E-01  
opls\_805 H805 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_820 C820 12.0110 0.000 A 3.55000E-01 2.92880E-01  
opls\_822 C822 12.0110 0.000 A 3.55000E-01 2.92880E-01  
opls\_802 O802 15.9990 0.000 A 3.12000E-01 7.11280E-01  
opls\_838 H838 1.0080 0.000 A 0.00000E+00 0.00000E+00  
opls\_809 O809 15.9990 0.000 A 3.12000E-01 7.11280E-01  
[moleculetype]  
; Name nrexcl  
GTP 3  
[atoms]  
; nr type resnr residue atom cgnr charge mass  
1 opls\_800 1 GTP P00 1 2.6917 30.9738  
2 opls\_801 1 GTP O01 1 -1.0843 15.9990  
3 opls\_802 1 GTP O02 1 -0.9317 15.9990  
4 opls\_803 1 GTP H03 1 0.4401 1.0080  
5 opls\_804 1 GTP O04 1 -0.9164 15.9990  
6 opls\_805 1 GTP H05 1 0.4233 1.0080  
7 opls\_806 1 GTP O06 1 -1.2431 15.9990  
8 opls\_807 1 GTP P07 1 2.7415 30.9738  
9 opls\_808 1 GTP O08 1 -1.0672 15.9990  
10 opls\_809 1 GTP O09 1 -0.8893 15.9990  
11 opls\_810 1 GTP H0A 1 0.4202 1.0080  
12 opls\_811 1 GTP O0B 1 -1.1679 15.9990  
13 opls\_812 1 GTP P0C 1 2.7075 30.9738  
14 opls\_813 1 GTP O0D 1 -1.0502 15.9990  
15 opls\_814 1 GTP O0E 1 -0.9044 15.9990  
16 opls\_815 1 GTP H0F 1 0.4252 1.0080  
17 opls\_816 1 GTP O0G 1 -0.8231 15.9990  
18 opls\_817 1 GTP C0H 1 0.4870 12.0110  
19 opls\_818 1 GTP C0I 1 -0.0773 12.0110  
20 opls\_819 1 GTP O0J 1 -0.2361 15.9990  
21 opls\_820 1 GTP C0K 1 0.1904 12.0110  
22 opls\_821 1 GTP C0M 1 0.1719 12.0110  
23 opls\_822 1 GTP C0N 1 0.1224 12.0110  
24 opls\_823 1 GTP N0O 1 -0.4746 14.0070  
25 opls\_824 1 GTP C0P 1 0.3162 12.0110  
26 opls\_825 1 GTP N0Q 1 -0.0612 14.0070  
27 opls\_826 1 GTP C0R 1 -0.0422 12.0110  
28 opls\_827 1 GTP C0S 1 0.5194 12.0110  
29 opls\_828 1 GTP C0T 1 0.4328 12.0110  
30 opls\_829 1 GTP O0U 1 -0.1798 15.9990  
31 opls\_830 1 GTP N0V 1 -0.8079 14.0070  
32 opls\_831 1 GTP C0W 1 0.7577 12.0110  
33 opls\_832 1 GTP H0X 2 0.4725 1.0080  
34 opls\_833 1 GTP N0Y 2 -0.4346 14.0070  
35 opls\_834 1 GTP N0Z 2 -0.7282 14.0070  
36 opls\_835 1 GTP H10 2 0.4465 1.0080  
37 opls\_836 1 GTP H11 2 0.4465 1.0080  
38 opls\_837 1 GTP O12 2 -0.4651 15.9990  
39 opls\_838 1 GTP H13 2 0.4065 1.0080  
40 opls\_839 1 GTP O14 2 -0.4416 15.9990  
41 opls\_840 1 GTP H15 2 0.4070 1.0080  
[bonds]  
2 1 1 0.1480 439320.000  
3 1 1 0.1610 192464.000  
4 3 1 0.0945 462750.400  
5 1 1 0.1610 192464.000  
6 5 1 0.0945 462750.400  
7 1 1 0.1610 192464.000  
8 7 1 0.1610 192464.000  
9 8 1 0.1480 439320.000  
10 8 1 0.1610 192464.000  
11 10 1 0.0945 462750.400  
12 8 1 0.1610 192464.000  
13 12 1 0.1610 192464.000  
14 13 1 0.1480 439320.000  
15 13 1 0.1610 192464.000  
16 15 1 0.0945 462750.400  
17 13 1 0.1610 192464.000  
18 17 1 0.1270 367606.240  
19 18 1 0.1451 334720.000  
20 19 1 0.1360 284512.000  
21 20 1 0.1360 284512.000  
22 21 1 0.1367 456892.800  
23 19 1 0.1367 456892.800  
24 21 1 0.1381 357313.600  
25 24 1 0.1310 316486.128  
26 25 1 0.1320 312896.256  
27 26 1 0.1394 343088.000  
28 27 1 0.1490 334720.000  
29 24 1 0.1374 364844.800  
30 28 1 0.1229 476976.000  
31 28 1 0.1388 349782.400  
32 31 1 0.1365 374886.400  
33 31 1 0.1010 363171.200  
34 29 1 0.1354 385764.800  
35 32 1 0.1381 357313.600  
36 35 1 0.1010 363171.200  
37 35 1 0.1010 363171.200  
38 22 1 0.1364 376560.000  
39 38 1 0.0945 462750.400  
40 23 1 0.1364 376560.000  
41 40 1 0.0945 462750.400  
23 22 1 0.1424 392459.200  
29 27 1 0.1404 392459.200  
34 32 1 0.1339 404174.400

[angles]  
; ai aj ak funct c0 c1 c2 c3  
2 1 3 1 108.230 836.800  
1 3 4 1 108.500 460.240  
2 1 5 1 108.230 836.800  
1 5 6 1 108.500 460.240  
2 1 7 1 108.230 836.800  
1 7 8 1 120.500 836.800  
7 8 9 1 108.230 836.800  
7 8 10 1 102.600 376.560  
8 10 11 1 108.500 460.240  
7 8 12 1 102.600 376.560  
8 12 13 1 120.500 836.800  
12 13 14 1 108.230 836.800  
12 13 15 1 102.600 376.560  
13 15 16 1 108.500 460.240  
12 13 17 1 102.600 376.560  
13 17 18 1 114.540 581.660  
17 18 19 1 180.000 1338.880  
18 19 20 1 120.360 513.377  
19 20 21 1 106.500 585.760  
20 21 22 1 110.600 585.760  
18 19 23 1 120.000 585.760  
20 21 24 1 120.360 513.377  
21 24 25 1 112.400 527.184  
24 25 26 1 180.000 1338.880  
25 26 27 1 111.360 497.143  
26 27 28 1 120.670 475.972  
21 24 29 1 109.800 585.760  
27 28 30 1 120.400 669.440  
27 28 31 1 118.180 584.923  
28 31 32 1 121.600 585.760  
28 31 33 1 116.800 292.880  
24 29 34 1 126.200 585.760  
31 32 35 1 118.760 505.678  
32 35 36 1 119.800 292.880  
32 35 37 1 119.800 292.880  
21 22 38 1 120.000 585.760  
22 38 39 1 113.000 292.880  
19 23 40 1 120.000 585.760  
23 40 41 1 113.000 292.880  
19 23 22 1 107.300 585.760  
36 35 37 1 120.000 292.880  
29 34 32 1 112.200 585.760  
14 13 17 1 108.230 836.800  
22 23 40 1 120.000 585.760  
15 13 17 1 102.600 376.560  
27 29 34 1 132.400 585.760  
5 1 7 1 102.600 376.560  
9 8 12 1 108.230 836.800  
32 31 33 1 119.200 292.880  
26 27 29 1 111.000 585.760  
23 22 38 1 120.000 585.760  
3 1 5 1 102.600 376.560  
25 24 29 1 112.400 527.184  
9 8 10 1 108.230 836.800  
28 27 29 1 120.000 711.280  
14 13 15 1 108.230 836.800  
24 29 27 1 108.700 585.760  
21 22 23 1 107.300 585.760  
31 32 34 1 123.300 585.760  
22 21 24 1 107.700 585.760  
34 32 35 1 118.760 505.678  
10 8 12 1 102.600 376.560  
30 28 31 1 120.600 669.440  
3 1 7 1 102.600 376.560  
20 19 23 1 110.600 585.760

[dihedrals]  
; IMPROPER DIHEDRAL ANGLES  
; ai aj ak al funct c0 c1 c2 c3 c4 c5  
23 19 18 20 4 180.000 10.460 2  
37 35 32 36 4 180.000 10.460 2  
33 31 28 32 4 180.000 10.460 2  
35 32 31 34 4 180.000 10.460 2  
31 28 27 30 4 180.000 43.932 2  
26 27 28 29 4 180.000 10.460 2  
34 29 24 27 4 180.000 10.460 2  
24 21 20 22 4 180.000 10.460 2  
40 23 19 22 4 180.000 10.460 2  
38 22 21 23 4 180.000 10.460 2

[dihedrals]  
; PROPER DIHEDRAL ANGLES  
; ai aj ak al funct c0 c1 c2 c3 c4 c5  
28 27 29 24 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
28 27 26 25 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
25 24 21 22 3 20.920 0.000 -20.920 -0.000 -0.000 0.000  
25 24 21 20 3 8.786 0.000 -8.786 -0.000 -0.000 0.000  
18 17 13 14 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
18 17 13 15 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
18 17 13 12 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
29 27 26 25 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
29 24 25 26 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
29 24 21 22 3 20.920 0.000 -20.920 -0.000 -0.000 0.000  
29 24 21 20 3 8.786 0.000 -8.786 -0.000 -0.000 0.000  
32 31 28 27 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
32 31 28 30 3 25.476 0.000 -25.476 -0.000 -0.000 0.000  
32 34 29 27 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
32 34 29 24 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
22 23 19 18 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
23 22 21 20 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
22 23 19 20 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
23 19 18 17 3 7.845 -1.569 -6.276 -0.000 -0.000 0.000  
22 21 20 19 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
23 19 20 21 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
27 29 24 25 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
27 29 24 21 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
27 26 25 24 3 41.840 0.000 -41.840 -0.000 -0.000 0.000  
19 18 17 13 3 12.510 0.000 -12.510 -0.000 -0.000 0.000  
21 22 23 19 3 9.079 0.000 -9.079 -0.000 -0.000 0.000  
21 20 19 18 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
36 35 32 31 3 20.502 0.000 -20.502 -0.000 -0.000 0.000  
37 35 32 31 3 20.502 0.000 -20.502 -0.000 -0.000 0.000  
37 35 32 34 3 20.502 0.000 -20.502 -0.000 -0.000 0.000  
36 35 32 34 3 20.502 0.000 -20.502 -0.000 -0.000 0.000  
33 31 28 27 3 20.502 0.000 -20.502 -0.000 -0.000 0.000  
33 31 28 30 3 20.502 0.000 -20.502 -0.000 -0.000 0.000  
41 40 23 22 3 -0.444 3.833 0.728 -4.117 -0.000 0.000  
39 38 22 23 3 -0.444 3.833 0.728 -4.117 -0.000 0.000  
41 40 23 19 3 -0.444 3.833 0.728 -4.117 -0.000 0.000  
39 38 22 21 3 -0.444 3.833 0.728 -4.117 -0.000 0.000  
16 15 13 14 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
11 10 8 9 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
6 5 1 2 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
4 3 1 2 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
6 5 1 3 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
16 15 13 12 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
11 10 8 7 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
35 32 31 28 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
35 32 31 33 3 20.502 0.000 -20.502 -0.000 -0.000 0.000  
35 32 34 29 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
31 28 27 29 3 29.288 0.000 -29.288 -0.000 -0.000 0.000  
31 28 27 26 3 9.079 0.000 -9.079 -0.000 -0.000 0.000  
31 32 34 29 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
26 25 24 21 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
26 27 29 24 3 9.079 0.000 -9.079 -0.000 -0.000 0.000  
34 29 27 28 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
34 29 27 26 3 9.079 0.000 -9.079 -0.000 -0.000 0.000  
34 29 24 25 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
34 29 24 21 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
34 32 31 28 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
34 32 31 33 3 20.920 0.000 -20.920 -0.000 -0.000 0.000  
24 21 22 23 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
24 21 20 19 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
30 28 27 29 3 29.288 0.000 -29.288 -0.000 -0.000 0.000  
30 28 27 26 3 4.184 0.000 -4.184 -0.000 -0.000 0.000  
9 8 7 1 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
14 13 12 8 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
20 19 18 17 3 4.707 1.569 -6.276 -0.000 -0.000 0.000  
38 22 23 19 3 9.079 0.000 -9.079 -0.000 -0.000 0.000  
40 23 22 21 3 9.079 0.000 -9.079 -0.000 -0.000 0.000  
40 23 22 38 3 9.079 0.000 -9.079 -0.000 -0.000 0.000  
40 23 19 18 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
38 22 21 24 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
40 23 19 20 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
38 22 21 20 3 30.334 0.000 -30.334 -0.000 -0.000 0.000  
5 1 3 4 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
10 8 7 1 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
15 13 12 8 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
7 1 3 4 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
7 1 5 6 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
17 13 15 16 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
12 8 10 11 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
12 8 7 1 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
17 13 12 8 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
8 7 1 2 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
13 12 8 9 3 0.000 0.000 0.000 -0.000 -0.000 0.000  
13 12 8 10 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
8 7 1 3 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
8 7 1 5 3 1.176 3.527 0.000 -4.703 -0.000 0.000  
13 12 8 7 3 1.176 3.527 0.000 -4.703 -0.000 0.000

[pairs]  
2 4 1  
2 6 1  
4 5 1  
3 6 1  
2 8 1  
1 9 1  
4 7 1  
3 8 1  
1 10 1  
6 7 1  
5 8 1  
1 12 1  
7 11 1  
9 11 1  
7 13 1  
9 13 1  
8 14 1  
11 12 1  
10 13 1  
8 15 1  
8 17 1  
12 16 1  
14 16 1  
12 18 1  
14 18 1  
13 19 1  
16 17 1  
15 18 1  
17 20 1  
18 21 1  
18 22 1  
17 23 1  
19 24 1  
20 25 1  
23 24 1  
22 25 1  
21 26 1  
21 27 1  
20 29 1  
22 29 1  
24 28 1  
25 28 1  
21 34 1  
26 30 1  
24 32 1  
26 31 1  
19 38 1  
20 38 1  
18 40 1  
29 30 1  
27 32 1  
25 34 1  
29 31 1  
27 33 1  
26 34 1  
21 39 1  
20 40 1  
19 41 1  
21 40 1  
30 32 1  
28 34 1  
24 38 1  
23 39 1  
30 33 1  
28 35 1  
22 41 1  
29 35 1  
33 34 1  
31 36 1  
33 35 1  
31 37 1  
34 36 1  
34 37 1  
38 40 1

---

<div class="post-metadata">

**Author:** ![alevilla](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/alevilla/32/439_2.png) [@alevilla](https://gromacs.bioexcel.eu/u/alevilla)\
**Post date:** [October 18, 2022, 4:01pm UTC](https://gromacs.bioexcel.eu/t/ligand-lincs-error-help/4975/2 "2022-10-18T16:01:22Z")

</div>

Hi,  
As far as I understood you got LINCS error for the protein-ligand complex. Which atom is in position 1 in your gro file? Atom 1 can belong to the protein or to the ligand. This depends in which order you have the system in the gro file.  
You could visualize maybe it helps to tackle the problem.  
\Alessandra
