compute_instantaneous_pressure_tensor

torch_sim.quantities.compute_instantaneous_pressure_tensor(*, momenta, masses, system_idx, stress, volumes)

Compute forces on the cell for NPT dynamics.

This function calculates the instantaneous internal pressure tensor.

Parameters:

• momenta (torch.Tensor) – Particle momenta, shape (n_particles, 3)

• masses (torch.Tensor) – Particle masses, shape (n_particles,)

• system_idx (torch.Tensor) – Tensor indicating system membership of each particle

• stress (torch.Tensor) – Stress tensor of the system, shape (n_systems, 3, 3)

• volumes (torch.Tensor) – Volumes of the systems, shape (n_systems,)

Returns:

Instanteneous internal pressure tesnor [n_systems, 3, 3]

Return type:

Tensor