MoireStudio 1.0.0

Universal Twisted Electronic Structure Calculation Package

MoireStudio

MoireStudio is a general-purpose toolkit for twisted / moiré electronic-structure calculations.

It integrates:

• Geometry: commensurate-angle search, moiré supercell generation (POSCAR-based), moiré point visualization
• Relaxation: in-plane and out-of-plane relaxation patterns and relaxed structures (analytic framework integrated)
• Tight-binding / Wannier: twisted TB band structures from POSCAR or Wannier90-like models; dense and sparse workflows
• Continuum k·p: generic and template-based (TBG / tTMD) continuum models; band structures and Chern numbers
• Reproducibility: automatic run metadata logging (e.g., outputs/metadata.json) and standardized output files

Table of contents

• Requirements
• Installation
• Quick start
• Command-line interface
• Input file: input.json
• Modes & tasks
• Examples
• Outputs
• Parallelism & performance notes
• How to cite
• Troubleshooting

Requirements

• Python ≥ 3.9
• Core dependencies: numpy, scipy, matplotlib

For best performance, use a NumPy/SciPy build linked against optimized BLAS/LAPACK (e.g., MKL/OpenBLAS).

Installation

Option A: package install (recommended)

From the repository root:

pip install moirestudio-1.0.0-py3-none-any.whl

Option B: script execution

If you keep a script-style layout, you can run:

python driver.py --input input.json

Quick start

1. Prepare an input.json in your working directory.
2. Put required inputs under ./inputs (default) or set io.input_dir.
3. Run:

python driver.py --input input.json

The default output directory is ./outputs (override with io.output_dir).

Command-line interface

Typical commands:

python driver.py --input input.json
python driver.py --input input.json --quiet
python driver.py --input input.json --no-color
python driver.py --version
python driver.py --cite

Input file: input.json

MoireStudio uses a JSON file with separate mode and task fields.

{
  "mode": "struc | tb | kp | mono",
  "task": "gen_struc | find_com | band | chern",
  "theta_deg": 1.10,
  "io": {},
  "struc": {},
  "relax": {},
  "tb": {},
  "kp": {}
}

• theta_deg is a top-level key.
• Only the blocks relevant to the selected mode/task are required.

Common IO keys (io)

• io.input_dir (default ./inputs)
• io.output_dir (default ./outputs)
• io.fig_band (band figure filename; falls back to io.figure, then <task>.pdf)
• io.fig_moire (default moire_points.pdf)
• io.show_plots (default false)

Heterobilayer helper keys (used when struc.ihetero=true):

• io.t_prefix, io.b_prefix
• io.t_fermi_energy, io.b_fermi_energy

Structure block (struc)

Core selectors:

• struc.read_mode: "POSCAR" or "model"
• struc.read_layer: "bilayer" or "monolayer"
• struc.ihetero: true/false

POSCAR inputs:

• struc.pos_path (default io.input_dir)
• struc.pos_prefix (default "POSCAR")

Interlayer distance (angstrom):

• Use struc.d_0 (default 3.5), or
• Provide struc.d_AA and struc.d_AB (if missing, falls back to d_0).

Moiré supercell generation (task="gen_struc"):

• struc.zero_point (default [0,0])
• struc.lim (default 20)
• struc.search (default 0)
• struc.accurate (default 0.01)
• struc.if_gen_pos (default true)
• struc.write_by_hand (optional manual selection for Lm)

Commensurate-angle scan (task="find_com"):

• struc.max_angle (default 180)
• struc.min_angle (default 1)
• struc.lim (default 10)
• struc.step (default 0.01)
• struc.accurate (default 0.01)

Relaxation block (relax)

• relax.irelax: enable/disable relaxation
• relax.order_num: harmonic order (default 0)
• relax.kappa_parallel: in-plane relaxation strength parameter
• relax.kappa_perp: out-of-plane relaxation strength parameter
• Optional pattern indices:
  • relax.u_in_idxs
  • relax.u_out_idxs

TB block (tb)

Band / k-path:

• tb.k_path: list of fractional k-points
• tb.nk: number of k points along the path (default 121)
• tb.labels: labels for k nodes (optional)
• tb.ylim: plot energy window (optional)

Compute options:

• tb.cores (default 1)
• tb.isparse (default false)
• tb.inter_coe (default 1)
• tb.isymmetry (optional)
• tb.ioutwannier (optional; dense only)

Wannier-like model input:

"tb": {
  "wannier": {
    "prefix": "wannier90",
    "fermi_energy": 0.0
  }
}

If fermi_energy is omitted, MoireStudio may try reading inputs/FERMI_ENERGY; otherwise it defaults to 0.

k·p block (kp)

Two usage styles:

1. Template mode (recommended for standard models)

• kp.system_name: "TBG" or "tTMD"
• kp.lat_a, kp.valley_idx
• For tTMD: kp.omega, kp.V, kp.psi
• For TBG: kp.u1, kp.u2

2. Generic mode (fully explicit)

• kp.tr: truncation shell (default 3)
• kp.valley_pos: fractional coordinates (default [2/3, 1/3])
• kp.mono_lat: 2x2 real-space lattice vectors
• kp.V_z, kp.m_z: onsite terms
• Specify exactly one of:
  • kp.hv_a (Dirac-like 2-band), or
  • kp.mass: [mx, my] (effective-mass 1-band)

Couplings are specified in amplitude + phase form (phases in degrees):

• Interlayer: kp.inter_idxs, kp.inter_amps, kp.inter_phas
• Intralayer top: kp.intra_t_idxs, kp.intra_t_amps, kp.intra_t_phas
• Intralayer bottom: kp.intra_b_idxs, kp.intra_b_amps, kp.intra_b_phas

Band plotting:

• kp.k_path, kp.nk, kp.labels, kp.ylim
• kp.fermi_shift: number, or "max" / "min"

Chern number (task="chern"):

• kp.n_mesh (default 25)
• kp.band_index (default 1)

Modes & tasks

• mode="struc":

  • task="gen_struc": generate moiré supercell (optionally relaxed) and write POSCAR
  • task="find_com": scan commensurate angles and write lists/plots

• mode="tb":

  • task="band": TB band structure from POSCAR or Wannier model

• mode="kp":

  • task="band": continuum k·p band structure
  • task="chern": Chern number on a k-mesh

• mode="mono":

  • task="band": monolayer band structure from a Wannier model

Examples

A) Geometry: generate moiré structure

{
  "mode": "struc",
  "task": "gen_struc",
  "theta_deg": 21.79,
    "struc": {
    "lim": 50,
    "read_mode": "POSCAR",
    "read_layer": "bilayer",
    "ihetero": false,
    "d_AA": 3.60,
    "d_AB": 3.60,
    "if_plot": false,
    "zero_point": [0, 0]
  }
 }

B) Geometry: scan commensurate angles

{	
	"mode":"struc",
	"task": "find_com",      
	"struc":{
		"read_mode": "POSCAR",
		"step": 0.01,
		"lim":30,
		"accurate":5e-3,
		"max_angle": 23,
		"min_angle": 1
	}
}

C) TB: band structure

{
  "mode": "tb",
  "task": "band",
  "theta_deg": 21.79,
  "io": {
    "output_dir": "./outputs",
    "input_dir": "./inputs",
    "fig_band": "band.pdf"
  },
  "struc": {
    "read_mode": "WANNIER",
    "read_layer": "bilayer",
    "bilayer_num": 2,
    "ihetero": false,
    "d_AA": 3.60,
    "d_AB": 3.35,
    "lim": 80,
    "zero_point": [[0.0, 0.0],[0.0,0.0]],
    "if_plot": false
  },
  "tb": {
    "wannier": {
      "prefix": "wannier90"
    },
    "cores": 1,
    "isparse": false,
    "k_path": [[0,0,0],[0.333333,0.333333,0],[0.5,0.0,0],[0,0,0]],
    "nk": 121,
    "labels": ["G","K","M","G"],
    "ylim": [-3, 3]
  }
}

D) k·p: generic band structure (Dirac-like)

  {
  "mode": "kp",
  "task": "band",
  "theta_deg": 1.05,
  "io": { "output_dir": "./outputs", "fig_band": "kp_band.pdf" },
  "kp": {
    "tr": 5,
    "valley_pos": [-0.6666667, -0.3333333],
    "mono_lat": [[2.46, 0.0], [1.23, 2.130422493309719]],
    "hv_a": 2135.4,
    "valley_name": "K",
    "inter_idxs": [[0,0],[1,0],[1,1]],
    "inter_amps": [[[80,90],[90,80]], [[80,90],[90,80]], [[80,90],[90,80]]],
    "inter_phas": [[[0,0],[0,0]], [[0,-120],[120,0]], [[0,120],[-120,0]]],
    "k_path": [[0,0],[0.666666,0.333333],[0.5,0.5],[0,0]],
    "nk": 201,
    "labels": ["G","K","M","G"],
    "ylim": [-200, 200]
  }
}

E) k·p: Chern number

{
  "mode": "kp",
  "task": "chern",
  "theta_deg": 1.10,
  "io": { "output_dir": "./outputs" },
  "kp": {
    "tr": 3,
    "hv_a": 1.0,
    "V_z": 0.0,
    "m_z": 0.0,
    "valley_pos": [0.6666667, 0.3333333],
    "mono_lat": [[2.46, 0.0], [1.23, 2.13162820728]],
    "inter_idxs": [[0,0]],
    "inter_amps": [90],
    "inter_phas": [0],
    "intra_t_idxs": [],
    "intra_t_amps": [],
    "intra_t_phas": [],
    "intra_b_idxs": [],
    "intra_b_amps": [],
    "intra_b_phas": [],
    "n_mesh": 31,
    "band_index": 1
  },
  "relax": { "irelax": false }
}

Outputs

Typical outputs under io.output_dir (default ./outputs):

Band / k-path:

• BAND.dat (k-distance vs energy; band-by-band blocks)
• band.txt (raw eigenvalue arrays)
• k_vec.txt, k_dist.txt, k_node.txt
• k_labels.txt
• band figure (e.g., tb_band.pdf, kp_band.pdf)

Geometry:

• POSCAR (generated/copy depending on task)
• moiré points figure (e.g., moire_points.pdf)
• commensurate_angle.txt and comm_angles.pdf (for task="find_com")

Reproducibility:

• metadata.json (versions, BLAS backend, platform info, input hash, etc.)

Parallelism & performance notes

• TB parallelism: set tb.cores > 1.
• For batch jobs, set BLAS thread environment variables explicitly (e.g., OMP_NUM_THREADS, MKL_NUM_THREADS, OPENBLAS_NUM_THREADS).
• For large problems, consider sparse workflows (tb.isparse=true) where applicable.

How to cite

• Method paper: Phys. Rev. B 111, 075434 (2025), arXiv:2509.13114

Troubleshooting

• Unknown mode/task: ensure mode ∈ {struc, tb, kp, mono} and task matches the selected mode.
• k·p error about mass vs hv_a: you must specify exactly one of kp.mass or kp.hv_a.
• No plots: set io.show_plots=true, or open the saved figure files under outputs/.
• Parallel issues on Windows: try tb.cores=1 first and then increase; prefer WSL for HPC-like usage.