Mass

The mass of atomistic objects are associated with the "mass" or "mass/<variant>" name (see Variants), and must have the following metadata:

Metadata for "mass"

Metadata	Names	Description
keys	"_"	the keys must have a single dimension named "_", with a single entry set to 0. The "mass" quantity is always represented as a metatensor.torch.TensorMap with a single block.
samples	["system", "atom"]	the samples must be named ["system", "atom"], since "mass" is always per-atom. "system" must range from 0 to the number of systems given as input to the model. "atom" must range between 0 and the number of atoms/particles in the corresponding system. If selected_atoms is provided, then only the selected atoms for each system should be part of the samples.
components		the "mass" quantity must not have any components
properties	"mass	The "mass" quantity must have a single property dimension named "mass", with a single entry set to 0.

"mass" as model input

The following simulation engine can provide "mass" as inputs to the models:

ASE

LAMMPS

"mass" as model output

The following simulation engine can use the "mass" quantity as an output:

ASE

LAMMPS