Summary

DMRG output dataclass.

Summary dataclass

Summary(
    energy: float,
    state: MPS,
    energies: List[float] = list(),
    converged: bool = False,
    n_sweeps: int = 0,
    bond_dims: List[int] = list(),
    discarded_weights: List[float] = list(),
)

Bases: AlgorithmSummary

DMRG output.

Attributes:

Name	Type	Description
energy	float	Final ground-state energy (lowest Ritz value from the last sweep).
state	MPS	Optimised MPS after all sweeps.
energies	List[float]	Energy recorded at the end of each full sweep (forward + backward half-sweep).
converged	bool	True if |E_new - E_old| < opts.e_tol before n_sweeps was reached.
n_sweeps	int	Actual number of full sweeps performed.
bond_dims	List[int]	Bond dimensions of state after convergence (length L - 1).
discarded_weights	List[float]	Discarded weight at the center bond measured during each backward half-sweep (2-site scheme only; always 0.0 for 1-site).

Functions

serialize

serialize() -> Dict

Serialize the summary to a plain dict compatible with torch.save.

The MPS state is serialized via Network.serialize, which produces a weights_only-safe dict of tensors and primitives.

Returns:

Type	Description
Dict	Serialized summary with keys "version", "energy", "energies", "converged", "n_sweeps", "bond_dims", and "state".

deserialize classmethod

deserialize(data: Dict, device: str = 'cpu') -> Summary

Reconstruct a Summary from a dict produced by serialize.

Parameters:

Name	Type	Description	Default
data	Dict	Dict previously returned by serialize.	required
device	str	Device to place all MPS tensor blocks on. Defaults to 'cpu'.	'cpu'

Returns:

Type	Description
Summary	Reconstructed summary with the MPS state placed on device.

Raises:

Type	Description
ValueError	If data["version"] is not 1.

Serialization

import torch

payload = summary.serialize()
torch.save(payload, "result.pt")

# Reload
data    = torch.load("result.pt", weights_only=True)
summary = dmrg.Summary.deserialize(data, device="cpu")

See Also

• Options — input options.
• run — returns a Summary.