Final Parameters Combination Rules

[outburned]

Hello,

I noticed that the combination rule used in the final_parameters output file in QUBEKit is in the Amber format. For instance, this is how it's written in .xml and .gro file format respectively.

<NonbondedForce coulomb14scale="0.8333333333" lj14scale="0.5" combination="amber">

[ defaults ]
; nbfunc        comb-rule       gen-pairs       fudgeLJ fudgeQQ
1               2               no              1            0.83333333  

Is it possible to change the format of the combination rule to that of other force fields?

I want to solvate this molecule with a given water model.

[jthorton]

Hi @outburned, the nonbonded and torsional parameters output by qubekit are now optimised to work with the Amber style combination rules and changing this will probably degrade the performance of the parameters so it is not advised to change them. If you really wanted to though you could manually change the comb-rule in the gromacs file, or if you wanted to run using openmm you would have to use a custom nonbonded force to implement a different rule like the example here for simulating the OPLS force field.

[outburned]

Hi, thanks for the clarification!