Lammps Error: Illegal pair_style hdnnp

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1

Hi Lammps Community :slight_smile:
Im trying to do energy minimization of a ternary alloy and the potential i have been using is hdnnp(high dimensional neural network potential). This is just a small task to check the proper working and get familiar with hdnnp. Later on I will be conducting MD simulations on it.
I am using LAMMPS 64-bit 23Jun2022-MPI version on my windows. I have hdnnp support enabled (I could see that when in type <lmp -h> in command prompt and under pair style hdnnp is there). Also all the required files like input data file and scaling file , weight file are placed in one directory.
Although it worked perfectly fine on one fine day , the next day Iam facing an error . Iam attaching the input script file .

lammps
lammps1906Ă—898 18.6 KB

The error goes like this —>
LAMMPS (23 Jun 2022 - Update 4)
OMP_NUM_THREADS environment is not set. Defaulting to 1 thread. (src/comm.cpp:98)
using 1 OpenMP thread(s) per MPI task
Loaded 1 plugins from C:\Users\salun\AppData\Local\LAMMPS 64-bit 23Jun2022-MPI\plugins
clear
OMP_NUM_THREADS environment is not set. Defaulting to 1 thread. (src/comm.cpp:98)
using 1 OpenMP thread(s) per MPI task
Loaded 1 plugins from C:\Users\salun\AppData\Local\LAMMPS 64-bit 23Jun2022-MPI\plugins
units metal
boundary p p p
atom_style atomic
box tilt large
read_data “data.nn”
Reading data file …
orthogonal box = (0 0 0) to (12.184254 12.184254 12.184254)
1 by 1 by 1 MPI processor grid
reading atoms …
108 atoms
read_data CPU = 0.006 seconds
mass 1 24.305
mass 2 26.9815385
mass 3 28.0855
variable nnpDir string “E:\Al-Mg-Si-HDNNP\small cluster no vac\hdnnp-data”
pair_style hdnnp 10.6 dir {nnpDir} showew no resetew yes maxew 100000000 cflength 1.8897261258369282 cfenergy 0.03674932247495664 pair_style hdnnp 10.6 dir E:\Al-Mg-Si-HDNNP\small cluster no vac\hdnnp-data showew no resetew yes maxew 100000000 cflength 1.8897261258369282 cfenergy 0.03674932247495664 ERROR: Illegal pair_style command (src/ML-HDNNP/pair_hdnnp.cpp:178) Last command: pair_style hdnnp 10.6 dir {nnpDir} showew no resetew yes maxew 100000000 cflength 1.8897261258369282 cfenergy 0.03674932247495664

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The error “Illegal pair style command” does not mean that the pair style is not present. For that you would get a message of the format:

ERROR: Unrecognized pair style 'hdnnp' is part of the ML-HDNNP package which is not enabled in this LAMMPS binary. (src/force.cpp:275)

Instead, this usually means that you have too many or too few arguments or syntax errors or similar.

As far as I can tell, the problem is here:

It is almost always a bad idea to use directory or file names with blanks in them.
In this case, the variable is correctly defined, but then, when it is used as ${hdnnpDir}, the “protective” quotes are no longer there and thus LAMMPS sees 4 “words” instead of 1.

You should be able to work around this by adding an additional pair of quotation marks to the variable definition like this:

variable nnpDir string “'E:\Al-Mg-Si-HDNNP\small cluster no vac\hdnnp-data'”

Which will then expand into the path still wrapped in the single quotes (since the double quotes are stripped off when defining the variable).

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Now its working fine ! . Thank you very much for helping out @akohlmey