q734738781/elastic-property-workup

elastic-property-workup

Overview

Use this skill to build a finite-strain screening set and collect the calculation evidence needed for later elastic fitting. Do not use it when the real task is elastic-tensor fitting, uncertainty quantification, or equation-of-state work rather than controlled strain-job collection.

Quick Start

1. Start from one accepted relaxed bulk structure.
2. Decide up front whether the strain members will be evaluated as fixed-cell stress jobs or with an explicitly stated relaxation policy.
3. Generate the strain family explicitly with generate_strained_structures.
4. Prepare one consistent VASP stage across the whole strain set.
5. Dispatch as a batch and collect stress/energy outputs with a focused pymatgen parser.

Allowed tools

• generate_strained_structures
• vasp_prepare
• remote_submission
• remote_submission_batch

Workflow

1. Define the strain family explicitly

• Use explicit deformation matrices when the study has a published protocol.
• Use mode/value grids only when the intended strain amplitudes are already justified.
• Record the actual strain amplitudes and matrix convention; “small strain” is not a reproducible input.

2. Choose the evaluation semantics before execution

• For ordinary finite-strain elastic screening, default to strained-structure single-point/stress collection rather than quietly relaxing each strained cell.
• If the scientific protocol requires internal-coordinate relaxation or another non-default treatment, state that explicitly and keep it uniform across the whole set.
• Do not mix fixed-cell stress jobs and relax-style jobs inside one comparison set without separating the results.

3. Keep execution uniform

• Apply one method contract across the whole strain set.
• Keep the same k-point density, ENCUT, spin treatment, DFT+U, and dispersion policy across every strain member.

4. Collect, do not overclaim

• A focused pymatgen Vasprun/Outcar parser separates failed strain points from usable ones.
• This skill stops at collected energies/forces/stresses; it does not fit elastic constants itself.
• Keep a ledger of which strained member produced usable stress/energy output and which failed.
• When a single total-energy scalar is needed from structured parser output, use E0 by default.

Method-critical defaults

• Keep the unstrained reference and every strained member on the same magnetic and electronic-structure footing.
• Report the actual strain matrices used; “small strain” is not specific enough for later fitting or reproduction.
• Keep the stress-vs-relax semantics explicit in the final handoff; elastic fitting cannot be audited without that distinction.
• Report the stress/energy units and the reference strain convention together.

Output Contract

Return:

• strained structure batch root
• execution root
• stress/energy parser summary path
• explicit strain-matrix ledger
• whether the stage used fixed-cell stress evaluation or an explicitly relaxed protocol

References

• Treat tensor fitting and uncertainty analysis as a downstream analysis stage, not as an implicit promise of this skill.