# \[ERROR\] No default U-B types and Proper Dih. types

**URL:** <https://gromacs.bioexcel.eu/t/error-no-default-u-b-types-and-proper-dih-types/6404>\
**Category:** User discussions\
**Tags:** mdp-parameters, mdrun\
**Created:** [May 15, 2023, 6:53am UTC](https://gromacs.bioexcel.eu/t/error-no-default-u-b-types-and-proper-dih-types/6404 "2023-05-15T06:53:55Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![kaye.conejos](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/kaye.conejos/32/2159_2.png) [@kaye.conejos](https://gromacs.bioexcel.eu/u/kaye.conejos)\
**Post date:** [May 15, 2023, 6:53am UTC](https://gromacs.bioexcel.eu/t/error-no-default-u-b-types-and-proper-dih-types/6404/1 "2023-05-15T06:53:55Z")

</div>

GROMACS version: gromacs/2021.4\_cuda-11.4.3 [supercomputer]  
GROMACS modification: No

Hello everyone! I am currently trying to the prepare protein-ligand complex. As I tried to do the grompp command, I’ve encountered 24 errors. [See below] I am using the latest CHARMM folder (jul2021) and have used the CGenFF in generating the .str file. I’d be happy if anyone could help. Thanks!

GROMACS is free software; you can redistribute it and/or modify it  
under the terms of the GNU Lesser General Public License  
as published by the Free Software Foundation; either version 2.1  
of the License, or (at your option) any later version.

GROMACS: gmx grompp, version 2021.4  
Executable: /opt/hpcc/GPU\_P40/gromacs/2021.4\_cuda-11.4.3/bin/gmx  
Data prefix: /opt/hpcc/GPU\_P40/gromacs/2021.4\_cuda-11.4.3  
Working dir: /scratch1/kaye.conejos/trial1/mdd  
Command line:  
gmx grompp -f ions.mdp -c solv.gro -p topol.top -o ions.tpr

Ignoring obsolete mdp entry ‘title’  
Ignoring obsolete mdp entry ‘ns\_type’

NOTE 1 [file ions.mdp]:  
With Verlet lists the optimal nstlist is \>= 10, with GPUs \>= 20. Note  
that with the Verlet scheme, nstlist has no effect on the accuracy of  
your simulation.

Setting the LD random seed to -22025737

Generated 167799 of the 167910 non-bonded parameter combinations  
Generating 1-4 interactions: fudge = 1

Generated 117519 of the 167910 1-4 parameter combinations

ERROR 1 [file unl.itp, line 169]:  
No default U-B types

ERROR 2 [file unl.itp, line 170]:  
No default U-B types

ERROR 3 [file unl.itp, line 174]:  
No default U-B types

ERROR 4 [file unl.itp, line 186]:  
No default U-B types

ERROR 5 [file unl.itp, line 228]:  
No default U-B types

ERROR 6 [file unl.itp, line 230]:  
No default U-B types

ERROR 7 [file unl.itp, line 234]:  
No default Proper Dih. types

ERROR 8 [file unl.itp, line 235]:  
No default Proper Dih. types

ERROR 9 [file unl.itp, line 236]:  
No default Proper Dih. types

ERROR 10 [file unl.itp, line 237]:  
No default Proper Dih. types

ERROR 11 [file unl.itp, line 238]:  
No default Proper Dih. types

ERROR 12 [file unl.itp, line 239]:  
No default Proper Dih. types

ERROR 13 [file unl.itp, line 240]:  
No default Proper Dih. types

ERROR 14 [file unl.itp, line 242]:  
No default Proper Dih. types

ERROR 15 [file unl.itp, line 244]:  
No default Proper Dih. types

ERROR 16 [file unl.itp, line 245]:  
No default Proper Dih. types

ERROR 17 [file unl.itp, line 246]:  
No default Proper Dih. types

ERROR 18 [file unl.itp, line 247]:  
No default Proper Dih. types

ERROR 19 [file unl.itp, line 254]:  
No default Proper Dih. types

ERROR 20 [file unl.itp, line 258]:  
No default Proper Dih. types

ERROR 21 [file unl.itp, line 260]:  
No default Proper Dih. types

ERROR 22 [file unl.itp, line 270]:  
No default Proper Dih. types

ERROR 23 [file unl.itp, line 271]:  
No default Proper Dih. types

ERROR 24 [file unl.itp, line 272]:  
No default Proper Dih. types

Excluding 3 bonded neighbours molecule type ‘Protein\_chain\_A’

Excluding 3 bonded neighbours molecule type ‘Protein\_chain\_B’

Excluding 3 bonded neighbours molecule type ‘Protein\_chain\_C’

Excluding 3 bonded neighbours molecule type ‘Protein\_chain\_D’

Excluding 3 bonded neighbours molecule type ‘UNL’

Excluding 2 bonded neighbours molecule type ‘SOL’

NOTE 2 [file topol.top, line 59]:  
System has non-zero total charge: -4.000000  
Total charge should normally be an integer. See  
[Floating point arithmetic — GROMACS webpage https://www.gromacs.org documentation](http://www.gromacs.org/Documentation/Floating_Point_Arithmetic)  
for discussion on how close it should be to an integer.

There were 2 notes

* * *

Program: gmx grompp, version 2021.4  
Source file: src/gromacs/gmxpreprocess/grompp.cpp (line 1963)

Fatal error:  
There were 24 errors in input file(s)