Thanks for everyone's help as ever. However, another wild stab in the dark question.
I've been having difficulty running an indentation into a block of atoms I've (now successfully) managed to get into a simulation from a data file.
The sim runs fine using lmp_serial, or a small number of processors. On a larger number of processors however the thing blows up and I get a
"Lost atoms" error message, even before the 0th timestep thermo output is printed.
Any idea what it could be, or what I could look at changing? It's not the first time I've seen this kind of thing, but fiddling with number of processors usually fixed it. Not so this time however.
Any ideas much appreciated.