LINVARIANT is a Universal model generator, in the field of computational condensed matter physics.
INVARIANT are such objects though we construct with the help of coordinate systems turn out to be independent of coordinates.
L is to memorize famous physicist Lev Davidovich Landau (22 January 1908 – 1 April 1968).

• Utilizing the Group Theory, it mathematically modeling physics systems such as Lattice, Electron, Spin and their coupling systems.
• LINVARIANT generates symmetry adapted microscopic or phenomenological models.
• LINVARIANT creates DFT training sets for the model fitting.
• LINVARIANT has numerical solvers running on the model, such as MC, MD, Exact diagnalization, Minimization, and et al..
• For large scale calculations, LINVARIANT exports the symbolic models into FORTRAN/C++ modules together with FORTRAN/C++ solvers, buiding files.

• Displacement and magnetic modes analysis
• INVARIANT generator (couplings among distortion, strain and magnetic)
• Modulate modes in supercell, generate initial Domain walls (DWs) structures for Density Functional Theory (DFT) codes
• Landau model builder, Generate DFT training sets by phonon and magnetic frozen-in.
• Heisenberg model with DM model builder
• Tight-Binding model builder
• Finite Element Method (FEM), Minimization, molecular dynamics (MD), Monte Carlo (MC), and Finite Differences nonlinear solver on large scale continuous model
• Generate Fortran source code from mathematica
• openmp parallelization
• dynamics under external electric field
• Jij of Heisenberg model from DFT, in Liechtenstein manner
• Unfolding
• phonon/magnon calculations from DFT input
• X ray diffraction simulation
• Nudged Elastic Bands (NEB) and Growing String Method (GSM) to explore the phase transition, dynamics, and domain wall structures
• Mollwide projection
• Examples: Boracite, Perovskite (To be added: Spinel, Rutile, Pyrochlore)

• implement LLG dynamics
• implement k dot p model builder
• interface to exact diagonalization method
• adding Atomistic Green's Function (AGF) method to study scattering and ultrafast non-equilibrium dynamics
• including electron phonon coupling (EPC) by fitting phonon dependent Tight-Binding (TB) model from DFT molecular dynamics (MD).

• Peng Chen - [email protected]
• Sergey Artyukhin - [email protected]
  

• Hongjian Zhao - [email protected]
• Laurent Bellaiche - [email protected]

See also the list of contributors who participated in this project.