schnetpack

Structure attributes

`properties.Z`	nuclear charge
`properties.R`	atom positions
`properties.cell`	unit cell
`properties.pbc`	periodic boundary conditions
`properties.idx_m`	indices of systems
`properties.idx_i`	indices of center atoms
`properties.idx_j`	indices of neighboring atoms
`properties.Rij`	vectors pointing from center atoms to neighboring atoms
`properties.n_atoms`	number of atoms

Return conversion factor for given units