# Fatal Error in Ligand
**URL:** https://ask.bioexcel.eu/t/fatal-error-in-ligand/2857
**Category:** General Topics in Molecular Dynamics
**Created:** [March 17, 2021, 4:18am UTC](https://ask.bioexcel.eu/t/fatal-error-in-ligand/2857 "2021-03-17T04:18:10Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@imamsamodra](https://ask.bioexcel.eu/u/imamsamodra)
#### Post date: [March 17, 2021, 4:18am UTC](https://ask.bioexcel.eu/t/fatal-error-in-ligand/2857/1 "2021-03-17T04:18:11Z")
Hi everyone,
I’m have a some problem when I try to run parameterization using Amber.
here the log file:
------- .R\.A\ and .R\.A\
FATAL: Atom .R\.A\ does not have a type.
FATAL: Atom .R\.A\ does not have a type.
FATAL: Atom .R\.A\ does not have a type.
Failed to generate parameters
Parameter file was not saved.
I already try to change the atom type but it doesn’t work.
---
### Author:  [@sonja.zrilic](https://ask.bioexcel.eu/u/sonja.zrilic)
#### Post date: [March 22, 2021, 5:12pm UTC](https://ask.bioexcel.eu/t/fatal-error-in-ligand/2857/2 "2021-03-22T17:12:57Z")
Hello!
I recognize that this is LEaP output text, and I believe I know what’s the problem.
I see your residue name is LIG, so I have to assume that you are using a non-standard ligand. For those, you have to build topology and charges manually. AmberTools has a program [Antechamber](http://ambermd.org/tutorials/basic/tutorial4b/) you can use for that, check out the hyperlink. The problem you’re experiencing in LEap will be solved once Antechamber creates atom types.
I see this was posted 6 days ago, so I hope you already managed to solve the problem. If not, I hope this helps.
Best regards,
Sonja