Public API

This page is the curated, stable public API surface of MPSKit — the symbols that are exported and intended for direct use. Each entry links to its full docstring in the Library index. The category reference pages (States, Operators, Ground-state algorithms) group the same docstrings by topic.

Note

Anything not listed here (or marked internal in the Library index) is not part of the public API and may change without notice.

States

The matrix product state types — finite, infinite, windowed, and multi-line.

FiniteMPS, InfiniteMPS, WindowMPS, MultilineMPS

Operators and Hamiltonians

Matrix product operators and Hamiltonians, finite and infinite, plus the wrappers used to build time-dependent and summed operators.

AbstractMPO, MPO, FiniteMPO, InfiniteMPO, MultilineMPO, MPOHamiltonian, FiniteMPOHamiltonian, InfiniteMPOHamiltonian, JordanMPOTensor, MultipliedOperator, TimedOperator, UntimedOperator, LazySum

Environments

The caches that store partially contracted tensor networks and are reused throughout the algorithms; see the concept page on Environments for why they exist.

environments

Ground states and boundaries

The ground-state search and 2D leading-boundary interface, and the DMRG/VUMPS/IDMRG family of algorithms that implement it.

find_groundstate, leading_boundary, approximate, VUMPS, VOMPS, DMRG, DMRG2, IDMRG, IDMRG2, GradientGrassmann

Bond dimension

Expanding or truncating a state's virtual spaces, and the algorithms that drive it.

changebonds, OptimalExpand, RandExpand, SvdCut, VUMPSSvdCut

Time evolution

Real- and imaginary-time evolution drivers and the algorithms and MPO approximations that implement them.

time_evolve, timestep, make_time_mpo, TDVP, TDVP2, WI, WII, TaylorCluster

Excitations

The excitation interface and the quasiparticle-ansatz and finite-excited-state algorithms that produce excited states on top of a ground state.

excitations, FiniteExcited, QuasiparticleAnsatz, ChepigaAnsatz, ChepigaAnsatz2

Linear problems and spectral functions

Solving the MPS linear problems behind dynamical/spectral quantities, such as propagators and susceptibilities.

propagator, DynamicalDMRG, NaiveInvert, Jeckelmann, exact_diagonalization, fidelity_susceptibility

Observables and analysis

Extracting physical quantities and analysis diagnostics from an MPS — expectation values, correlators, spectra, and entanglement.

expectation_value, correlator, variance, correlation_length, marek_gap, transfer_spectrum, entropy, entanglement_spectrum

Boundary conditions

Converting an infinite MPO into a finite one of a given length, either wrapping it (periodic) or truncating it (open).

open_boundary_conditions, periodic_boundary_conditions

Utility

Periodic and windowed array containers, virtual/physical space accessors, and a compact "braille" visualization of an MPO's sparsity structure.

PeriodicArray, PeriodicVector, PeriodicMatrix, WindowArray, left_virtualspace, right_virtualspace, physicalspace, braille