A parameter is needed to control whether to output a trajectory file during MD calculations in ABACUS #7877

Background

I need to perform MD calculations to verify the structural stability after a number of simulation steps, as well as to identify possible crystal‑structure phase transitions. Accordingly, I hope to obtain the averaged structure by averaging the last several snapshots output from MD runs.

Currently, ABACUS outputs separate STRU files for every individual MD step. These files need to be aggregated into a single file for subsequent analysis of crystal‑structure properties along the MD trajectory. Therefore, a parameter is required to control whether STRU snapshots are written into one consolidated trajectory file during MD calculations in ABACUS.

Describe the solution you'd like

Besides the existing parameter out_freq_ion, add a new parameter (e.g., out_trajectory) to enable output of a unified trajectory file that contains all STRU snapshots.

Task list only for developers

• Notice possible changes of behavior
• Explain the changes of codes in core modules of ESolver, HSolver, ElecState, Hamilt, Operator or Psi

Notice Possible Changes of Behavior (Reminder only for developers)

No response

Notice any changes of core modules (Reminder only for developers)

No response

Notice Possible Changes of Core Modules (Reminder only for developers)

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Additional Context

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Task list for Issue attackers (only for developers)

• Review and understand the proposed feature and its importance.
• Research on the existing solutions and relevant research articles/resources.
• Discuss with the team to evaluate the feasibility of implementing the feature.
• Create a design document outlining the proposed solution and implementation details.
• Get feedback from the team on the design document.
• Develop the feature following the agreed design.
• Write unit tests and integration tests for the feature.
• Update the documentation to include the new feature.
• Perform code review and address any issues.
• Merge the feature into the main branch.
• Monitor for any issues or bugs reported by users after the feature is released.
• Address any issues or bugs reported by users and continuously improve the feature.