Model Method Overview¶

Pages in This Section¶

Basis Sets

Purpose¶

This page explains how method information is organized in the ModelMethod hierarchy and how to read that structure within a NOMAD archive.

For full section and quantity definitions, use the schema navigation references above.

Reading the Hierarchy¶

Method identity is expressed by fields such as name, type, and the relevant method-family quantities.
Numerical realization remains attached through numerical_settings, so the method description and its practical setup remain connected without being merged into the same conceptual layer.
Writing the Hamiltonian as \(H = H_0 + \sum_i H_i\), the additive terms \(H_i\) (dispersion corrections, solvation models, Hubbard interactions, DFT-specific corrections, force-field potentials) are stored as HamiltonianTerm sections under contributions. Full methods are not terms and cannot be nested there. Modifications that reshape \(H_0\) itself rather than adding a separable term are kept in their own typed subsections instead; the relativistic treatment (ModelMethodElectronic.relativity) is the current example.
Composite multi-method schemes (for example ONIOM-style embedding) are not modeled by nesting methods inside each other; a dedicated container section with explicitly enumerated member subsections is planned for those.

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

Interpreting Method Data in Archives¶

Method identity is carried by fields such as name, type, and the relevant method-family quantities.
Numerical realization remains attached through numerical_settings, so archive readers can distinguish model semantics from solver/setup choices.
References to related ModelSystem or Outputs sections are best understood as links between archive components rather than duplicated method descriptions.

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