how to find out the force field parameters for MD Simulations in lammps?
using LJ models
How to find/calculate the above parameters? kindly explain
Hey Rajesh,
First you need to figure out what is the form of your non-bonded and bonded potentials you are going to use to model interactions in your system. Then you compare with the available forms in LAMMPS. You can find the existing non-bonded interactions in the pair_style page of the manual (Pair Styles — LAMMPS documentation). Similarly, for the bonded interactions, check the bond_style, angle_style and dihedral_style pages of the manual (assuming you dont have impropers from looking at your table).
Once you figure out the potential form, you can figure out how to specify the parameters (I mean, in which order they should be specified). You should also beware of any unit conversion you may need to do depending on the units you are using (see units command — LAMMPS documentation).
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Actually, I would like to know that the how to get the values which are listed in the table by because I want to calculate that parameter for polycarbonate also.
ahh, but for this you need to read the official publication of the DREIDING force-fields (https://pubs.acs.org/doi/pdf/10.1021/j100389a010). There they should explain how to calculate the parameters for each interaction you have in your specific system.
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