NVTNoseHooverState

class torch_sim.integrators.nvt.NVTNoseHooverState(positions, masses, cell, pbc, atomic_numbers, system_idx, momenta, energy, forces, chain, _chain_fns)

Bases: MDState

State information for an NVT system with a Nose-Hoover chain thermostat.

This class represents the complete state of a molecular system being integrated in the NVT (constant particle number, volume, temperature) ensemble using a Nose-Hoover chain thermostat. The thermostat maintains constant temperature through a deterministic extended system approach.

Variables:

• positions (Tensor) – Particle positions with shape [n_particles, n_dimensions]

• masses (Tensor) – Particle masses with shape [n_particles]

• cell (Tensor) – Simulation cell matrix with shape [n_dimensions, n_dimensions]

• pbc (bool) – Whether to use periodic boundary conditions

• momenta (Tensor) – Particle momenta with shape [n_particles, n_dimensions]

• energy (Tensor) – Energy of the system

• forces (Tensor) – Forces on particles with shape [n_particles, n_dimensions]

• chain (NoseHooverChain) – State variables for the Nose-Hoover chain thermostat

Parameters:

• positions (Tensor)

• masses (Tensor)

• cell (Tensor)

• pbc (bool)

• atomic_numbers (Tensor)

• system_idx (Tensor)

• momenta (Tensor)

• energy (Tensor)

• forces (Tensor)

• chain (NoseHooverChain)

• _chain_fns (NoseHooverChainFns)

Properties:

velocities: Particle velocities computed as momenta/masses

Has shape [n_particles, n_dimensions]

Notes

• The Nose-Hoover chain provides deterministic temperature control

• Extended system approach conserves an extended energy quantity

• Chain variables evolve to maintain target temperature

• Time-reversible when integrated with appropriate algorithms

property velocities: Tensor

Velocities calculated from momenta and masses with shape [n_particles, n_dimensions].