[option] Section

Last updated: October 16, 2026

For the calculation codes supported by each *_step_flag, see Interface > Option compatibility.

Name	Value	Default	Description
`rslt_out`	`always`, `cycle`, `off`	`always`	(since version 1.5.0) Specifies when `cryspy_rslt` and `cryspy_rslt_energy_asc` are written. `always`: Write whenever a structure’s result is recorded. `cycle`: Write at the end of each generation in EA/EA-vc or each selection in BO/LAQA (no output in RS). `off`: Do not write these text files. Result pickle data is saved for all settings.
`check_mindist_opt`	bool	`True`	If True, a mindist constraint is checked after structure relaxation.
`stop_chkpt`	int	0	CrySPY stops at a specified check point.
`load_struc_flag`	bool	`False`	If True, load initial structures from `./data/pkl_data/init_struc_data.pkl`. Structure IDs must be consecutive integers starting from `0`. The maximum number of loaded structures is `n_pop` for EA/EA-vc and `tot_struc` otherwise. Exceeding this limit raises an error; any shortfall is filled by random structure generation. See Features > Loading Initial Structures for details.
`stop_next_struc`	bool	`False`	If True, CrySPY does not submit jobs for next structures, but jobs for next stage are submitted.
`backup_interval`	int	RS: 0 Other: 1	(since version 1.5.0) Interval between automatic backups in generations for EA/EA-vc or selections for BO/LAQA. Set to 0 to disable automatic backups.
`energy_output_interval`	int	1	(since version 1.5.0) Interval in generations for outputting the energy plot in EA and the convex-hull plot and hull-distance file in EA-vc. Set to 0 to disable these automatic outputs. The convex hull and hull distances in EA-vc are still calculated every generation.
`recalc`	int [int …]	`None`	Specify structure IDs if you want to recalculate or continue optimization.
`append_struc_ea`	bool	`False`	If True, append structures by EA.
`energy_step_flag`	bool	`False`	If True, save energy_step_data in `./data/pkl_data/energy_step_data.pkl`. In QE, `pv_term = True` cannot be used together with `energy_step_flag = True`.
`struc_step_flag`	bool	`False`	If True, save struc_step_data in `./data/pkl_data/struc_step_data.pkl`.
`force_step_flag`	bool	`False`	If True, save force_step_data in `./data/pkl_data/force_step_data.pkl`.
`stress_step_flag`	bool	`False`	If True, save stress_step_data in `./data/pkl_data/stress_step_data.pkl`.
`seed`	int	`None`	(since version 1.5.0) Seed for the random number generator. Must be an integer between 0 and 2**32 - 1.