Trouble with dumping Improper angles during a MD run

Good afternoon LAMMPS mailing list,

I am having trouble with the dump command that should output the improper angles in my simulation.

I am currently simulating a coarse-grained P3HT and I was able to output bond, angle and dihedral between different coarse-grained particles of interest during the run.

The way I have outputted the angular distances between particles of interest, for example, is the following:

compute d1 all property/local dtype datom1 datom2 datom3 datom4
compute d2 all dihedral/local phi
dump 4 all local 100 _Dihedral_Analysis index c_d1[1] c_d1[2] c_d1[3] c_d1[4] c_d1[5] c_d2[]

In my external data file, ( I have properly defined all the bond, angle, dihedral and improper data and the atom ID are all consistently labeled accordingly. Therefore, it is no doubt that I can use compute improper/local command and have my script output a dump file that consists of the improper angles during the MD run.

However, specifically, for improper angles, I am received an error that states:

ERROR: Dump local compute does not calculate local array

and the error is coming from

dump 5 all local 100 *_Improper_Analysis index c_i1[1] c_i1[2] c_i1[3] c_i1[4] c_i1[5] c_i2[1]

I have attached a small data file along with my lammps script that reproduces this error.

I searched through the manual and mailing list and considering I have defined my atom ID’s which the improper potential should act upon, I am having trouble understanding this error.

Note that in my attached lammps script, I removed the ensembles and I zeroed out all the pairwise, bond, angle, dihedrals and improper potentials acting between particles. Hence, the attached lammps script is a static with no time integration.

If anyone could provide me with a clue to resolving this issue of dumping improper angles, it would be much appreciated.

Thank you.


Masato Koizumi

P.S. The LAMMPS version I am running this with is 16Mar18. I apologize for running with such an old version of LAMMPS; it is the one that is currently installed in my cluster for the time being. (2.16 KB) (147 KB)