# Error in loading parameters for tleap

**URL:** https://ask.bioexcel.eu/t/error-in-loading-parameters-for-tleap/3160
**Category:** General Topics in Molecular Dynamics
**Created:** [July 13, 2021, 8:00am UTC](https://ask.bioexcel.eu/t/error-in-loading-parameters-for-tleap/3160 "2021-07-13T08:00:20Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![khhel100](https://avatars.discourse-cdn.com/v4/letter/k/e68b1a/32.png) [@khhel100](https://ask.bioexcel.eu/u/khhel100)
#### Post date: [July 13, 2021, 8:00am UTC](https://ask.bioexcel.eu/t/error-in-loading-parameters-for-tleap/3160/1 "2021-07-13T08:00:20Z")

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error:

Error!  
For atom (.R\<UNK 1\>.A\<O39 39\>) could not find vdW (or other) parameters for type (O.3)

my build.leap file:

source leaprc.protein.ff14SB  
source leaprc.water.tip3p  
source leaprc.gaff  
source leaprc.lipid14  
loadoff …/parameters/Doxorubicin\_pos.off  
loadamberparams frcmod.ionsjc\_tip3p  
drug = loadpdb dox\_pos\_center.pdb  
bilayer = loadpdb DMPC\_72\_relax.pdb  
mol = combine { drug bilayer }  
set mol box {48.158000946044922 47.37200164794922 77.938003540039064}  
saveamberparm mol DMPC\_dox\_pos.prmtop DMPC\_dox\_pos.inpcrd  
quit