reax/c

Hi LAMMPS user,

I am trying to simulate Fe3O4 using a reactive force field. I never used a reactive force field before. I am getting the error :

pair_style reax/c NULL checkqeq yes
ERROR: Unknown pair style reax/c (src/force.cpp:263)

Last command: pair_style reax/c NULL checkqeq yes)

Below is my part of input script

-------------- Initialize Simulation ------------

echo both
units metal # set ‘metal’ units (Angstrom,ps timescale)
dimension 3
boundary p p p # periodic BCs
atom_style atomic
atom_modify map array
neighbor 1.0 bin
neigh_modify delay 0 every 1 check yes # neighbor command modifies potential’s natural cutoff_needed?

----------------------- ATOM DEFINITION ----------------------------

read_data Fe3O4_shell.lmp
write_dump all atom all_atom.lammpstrj

--------------- Creat Atoms / Geometry -----------------------

mass 1 55.847
mass 2 15.999
region rPKA sphere 25.6009 117.537 105 1.4 # Create spherical region ‘rpka’ at x, y, x with radius (157174 particle index)

------------------Define Interatomic Potential -----------------

pair_style reax/c NULL checkqeq yes
pair_coeff 1 2 ffield.reax.Fe_O_C_H Fe O

I have googled and found some suggestion for compile USER-REAXC.
Is this Correct? If yes, can you suggest me how I can do this?
My LAMMPS version is
LAMMPS (8 Feb 2019)

Please study the LAMMPS manual. It contains detailed instructions on how to compile it. It also has a whole section dedicated to errors and warnings.
Axel

Dear Sir

I have compiled USER-REAXC

using “make yes-USER-REAXC”

then tried “make machine” and got the error message
Makefile:202: recipe for target ‘machine’ failed
make: *** [machine] Error 1

checked the package with “make ps”

it shows yes.

Do I need to mention in command line the package name for execution the input script? For my case, I use lmp_daily < in.txt.

does make serial work?

Dear Sir

I have compiled USER-REAXC

using “make yes-USER-REAXC”

then tried “make machine” and got the error message
Makefile:202: recipe for target ‘machine’ failed
make: *** [machine] Error 1

checked the package with “make ps”

it shows yes.

that is only part of the necessary steps. you also need a successful compilation and the resulting executable has to show that the corresponding pair style is available and the package installed when running it with the -h flag only. e.g. like this ./lmp_mpi -h

Do I need to mention in command line the package name for execution the input script? For my case, I use lmp_daily < in.txt.

no, but you a) need to pay better attention when reading the documentation. as the manual mentions, there is no “machine” configuration, and b) you must use the newly compiled (if you manage to get a successful compilation, that is) executable and not the one that you installed pre-compiled from a package server.

axel.

Dear USER

thank you for your immediate response. I am again working on the LAMMPS installation. just make sure, I am using desktop whose processor is Intel® Core™ i3-4130 CPU @ 3.40GHz × 4. should I go with make serial or make mpi?

Please read the manual and then make an informed decision. Either option may be applicable. It all depends on whether you want to run with MPI or not.
Axel.