NEIGHBOR_INDEX(:), NEIGHOBRS(:,:), PFT_NEIGHBOR
What do these arrays mean?
These refer to variables in the neighbor search algorithm in DES_TIME_MARCH, which determines the potential contact partners surrounding a given particle. Values are referenced using particle ID (usually “LL”) and/or neighbor ID (usually “CC”).
You can find their dimensions/components in the module discretelement.f. In general, if you are unsure about any DEM variable, it can be helpful to find its description in discretelement.f