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Model Method Overview

Purpose

This page explains how to use the ModelMethod hierarchy in hand-written schema data, without duplicating generated structure tables.

For full section and quantity definitions, use:

Rules and Invariants

  • Use name/type to identify the method family and subtype.
  • Keep Hamiltonian/model semantics in ModelMethod and subclasses.
  • Keep numerical control parameters under numerical_settings.
  • Use contributions for additive model terms instead of flattening all terms into one section.
  • When a concept has both a physical-model aspect and an implementation aspect, split them: keep the model identity in ModelMethod and the realization knobs in NumericalSettings.

Hierarchy Snapshot

Model Method Hierarchy (Generated)

Class Description
BaseModelMethod A base section used to define the abstract class of a Hamiltonian section.
ModelMethod A base section for the method-defining choices of a simulation.
ModelMethodElectronic A base section used to define the parameters of a model Hamiltonian used in electronic structure calculations (TB, DFT, GW, BSE, DMFT, etc).

Source reference: - Model Method (Schema Navigation) - Model Method Electronic (Schema Navigation)

Key Method Families

Key Method Families (Generated)

Family Section Class Description Generated Reference
DFT DFT A base section used to define the parameters used in a density functional theory (DFT) calculation. Model Method Electronic
TB TB A base section containing the parameters pertaining to a tight-binding (TB) model calculation. Model Method Electronic
HF HF Defines a Hartree-Fock (HF) calculation. Model Method Electronic
CC CC A base section used to define the parameters of a Coupled Cluster calculation. Model Method Electronic
CI CI Single-reference Configuration Interaction (CI) methods using atom-centered basis sets. Model Method Electronic
Wannier Wannier A base section used to define the parameters used in a Wannier tight-binding fitting. Model Method Electronic
Slater-Koster SlaterKoster A base section used to define the parameters used in a Slater-Koster tight-binding fitting. Model Method Electronic
GW GW A base section used to define the parameters of a GW calculation. Model Method Electronic
BSE BSE A base section used to define the parameters of a BSE calculation. Model Method Electronic
DMFT DMFT A base section used to define the parameters of a DMFT calculation. Model Method Electronic
Excited-State Methodology ExcitedStateMethodology A base section used to define the parameters typical of excited-state calculations. Model Method Electronic
Photon Photon A base section used to define parameters of a photon, typically used for optical responses. Model Method Electronic

Related generated references: - Model Method Electronic - Numerical Settings - Force Field

Parser and Normalization Guidance

  • Prefer explicit parser population of method-defining fields.
  • Use normalization to complete derived or cross-linked information, not to overwrite explicit parser intent.
  • Keep references to ModelSystem/Outputs sections by identity rather than data duplication.

Executable Example

from nomad_simulations.schema_packages.model_method import DFT
from nomad_simulations.schema_packages.numerical_settings import SelfConsistency


def build_model_method_overview_example() -> DFT:
    """Create a minimal DFT method section with SCF settings."""
    scf = SelfConsistency(n_max_iterations=80)
    method = DFT(
        name='DFT',
        type='KS',
        jacobs_ladder='GGA',
        numerical_settings=[scf],
    )
    return method