orientational dipole moment calculation

Dear all

In my system I have some water and I use atom style full and pair_style lj/charmm/coul/long

To calculate orientation of dipole moment of the atoms in my system (mu,
mux, ....) I use the following commands:

compute Mu sol property/atom mu mux muy muz

and then I dump the results as the following:

dump            Mu sol custom 100 MU,2N6.22Dec id type xu yu zu c_Mu[1]
c_Mu[2] c_Mu[3] c_Mu[4]

But I receive the following error:

ERROR: Compute property/atom for aidtom property that isn't allocated

Also when I don't use Compute property and just use the following dump

dump            Mu sol custom 100 MU.22Dec id type mu mux muy muz

I receive the following error:

ERROR: Dumping an atom property that isn't allocated

I would be grateful if I have your advice.

Thanks a lot for your time and attention,

Best Regards,


You need to use atom_style dipole.


When I use

atoms style: charge or dipole
pair style:  lj/charmm/coul/long/opt

I see:

Bond_style command when no bonds allowed (input.cpp:941)

and with using

atoms style:  dipole
pair style:  dipole/cut

I see

ERROR: KSpace style is incompatible with Pair style (kspace.cpp:146)

my kspace style is:pppm


Best Regards,


These errors came from parts of the input script that are not shown. It is difficult to comment without more info.

Please also re-read doc page more thoroughly.


The approach is nonsense. Your model has point charges, but the commands you refer to are for accessing point dipole properties. At best you can compute per molecule dipoles, but for that you would first have to program a corresponding compute.


i should also remind you that you asked *exactly* the same thing about
half a year ago and received a proper answer. trying something that
makes no sense, doesn't get any better over time.

to re-iterate. the dipole properties that you are referring to are
related to computing interactions between *explicit* point dipoles
(for example stockmayer fluids). of course, LAMMPS flexible
infrastructure allows you to *add* those to your potential, if you
want, but it *does not* compute them for you.