Dear Lammps Users,
I am trying to simulate a composite system containing 10 elements with different potentials and different data files. In this regard, i was using hybrid pair_style to establishing the interactions with three different eam/alloy potentials, morse and lj/cut. but i am constant encountered with the following error:
ERROR: All pair coeffs are not set (…/pair.cpp:238)
I request you to please help me out in getting rid of this error. please find the screenshot of my input script
adding the “info coeffs” command to your input can help you determine which sets of coefficients are missing.
please also note, that there are many discussion on the subject of the risks of liberally mixing and matching (many) different potentials in the mailing list archives. i suggest to dig through some of those to be aware of the potential significant errors resulting from this approach.
pair style hybrid may initially look like a godsent, but it has to be used with great care (as any great power).
Info coeffs showed that i missed out some pair coeffs. In correcting them, i am facing the following problem
pair_style hybrid eam/alloy eam/alloy eam/alloy morse 10 lj/cut 7.0
pair_coeff 15 15 eam/alloy 1 bmg.eam Cu Ti Zr Al Ni
lammps is popping up error saying that Incorrect args for pair coefficients (…/pair_eam_alloy.cpp:52).
please suggest me in this regard
many thanks in advance
that is the correct error. your input is incorrect.
please also see the discussions in the mailing list i pointed out to you. what you appear to be trying to do is ignoring some fundamental properties of EAM potentials and cannot be set up like that. they are not pair-wise additive potentials and their correct functioning is dependent “seeing” all of the contributions to the embedding term from all surrounding atoms. by using pair style hybrid you would be partitioning your system and those contributions are not available and thus rendering your model bogus.