Position

Atomic positions are associated with the "position" or "position/<variant>" name (see Variants), and must have the following metadata:

Metadata for "position"

Metadata

Names

Description

keys

"_"

the keys must have a single dimension named "_", with a single entry set to 0. The "position" quantity is always represented as a metatensor.torch.TensorMap with a single block.

samples

["system", "atom"]

the samples must be named ["system", "atom"], since "position" 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

"xyz"

The "position" quantity must have a single component dimension named "xyz", with three entries set to 0, 1, and 2. The position is always a 3D vector, and the order of the components is x, y, z.

properties

"position"

The "position" quantity must have a single property dimension named "position", with a single entry set to 0.

At the moment, positions are not integrated into any simulation engines.