Out of range atoms - cannot compute PPPM error

Hi all,

I saw that this error has been discussed in the mail list many times but I wonder one specific issue and will appreciate it if you can help me. I tried some of cases and realized that Out of range atoms - cannot compute PPPM error is due to assigned pair coefficients generally and also in my specific problem when I set the pair coefficients between the solid and liquid(water-copper) it works feasibly. But in this case I know that some interaction must occur between solid-liquid which I can’t observe when I set these coefficients as zero but otherwise the program will give that error. By the way I assume this error is due to bad dynamics or initialization of the problem rather than a fft or etc issue since I get same error when I run it on a single processor.

So do you agree that the coefficients must be non-zero between solid and liquid? If so, some of the commonly used potentials for this case in the literature don’t exist in lammps like spohr, as a result do you have any advice to set this type of interaction potential correctly using for example LJ or any other pair styles that you can tell? Please note that I also tried different combining rules in addition to Berloth like Kong’s to specify LJ parameters between copper and water once I defined copper-copper, O-O and H-H.

Tolga AKINER, BSc.

Bogazici University

Mechanical Engineering Department