Error: A bonded interaction should exist between atoms in Moltemplate

Hi, I’m a moltemplate user and trying to make LiTFSI data file using moltemplate to use OPLSAA force field.
My molecule has 6 types of atoms.
Li @atom:348
N @atom:193
O @atom:435
S @atom:434
C @atom:666
F @atom:667

So I assigned atom types each, but only ONE bonded interaction has an error.
It is S-N-S interaction.

They have bond type in the oplsaa.lt file, but they kept showing this error.
I checked every atom related to N because I thought N has some problems.
But none of atom types match with N, and when I erase S-N-S bonds, there’s no error.

Please help me with that. I’d appreciate it.

+) When I don’t use -checkff command to make data file, there’s a lack of one angle coefficient, but all bonds are contained in the file.
If it’s not really matter, I’ll ignore this error, but the angle information is of S-N-S bonds.

The correct way to discuss a Moltemplate problem is to raise an issue on the GitHub repository. For the sake of time, I’ll briefly explain the error here.

The error message clearly states that the oplsaa.lt force field file does not contain an angle coefficient for the S-N-S triple, nor a rule to assign an angle coefficient to it. So you either delete one of the bonds, or use the -nocheck option and run a simulation without that angle potential. You could also define a custom angle coefficient (and corresponding rule) to the opls-aa file, or check the literature for a modified version that includes the missing term.

1 Like

Thank you so much for your answer.
I figured out I have to custom not only angle section but also up to dihedral coefficients.