You may prepare initial data for bulk systems with VASP by:

dpgen init_bulk PARAM [MACHINE]

The MACHINE configure file is optional. If this parameter exists, then the optimization tasks or MD tasks will be submitted automatically according to MACHINE.json.

Basically init_bulk can be divided into four parts , denoted as stages in PARAM:

  1. Relax in folder 00.place_ele

  2. Perturb and scale in folder 01.scale_pert

  3. Run a short AIMD in folder

  4. Collect data in folder

All stages must be in order. One doesn’t need to run all stages. For example, you may run stage 1 and 2, generating supercells as starting point of exploration in dpgen run.

If MACHINE is None, there should be only one stage in stages. Corresponding tasks will be generated, but user’s intervention should be involved in, to manually run the scripts.

Following is an example for PARAM, which generates data from a typical structure hcp.

    "stages" : [1,2,3,4],
    "cell_type":    "hcp",
    "latt":     4.479,
    "super_cell":   [2, 2, 2],
    "elements":     ["Mg"],
    "potcars":      ["....../POTCAR"],
    "relax_incar": "....../INCAR_metal_rlx",
    "md_incar" : "....../INCAR_metal_md",
    "scale":        [1.00],
    "skip_relax":   false,
    "pert_numb":    2,
    "md_nstep" : 5,
    "pert_box":     0.03,
    "pert_atom":    0.01,
    "coll_ndata":   5000,
    "type_map" : [ "Mg", "Al"],
    "_comment":     "that's all"

If you want to specify a structure as starting point for init_bulk, you may set in PARAM as follows.

"from_poscar":	true,
"from_poscar_path":	"....../C_mp-47_conventional.POSCAR",

init_bulk supports both VASP and ABACUS for first-principle calculation. You can choose the software by specifying the key init_fp_style. If init_fp_style is not specified, the default software will be VASP.

When using ABACUS for init_fp_style, the keys of the paths of INPUT files for relaxation and MD simulations are the same as INCAR for VASP, which are relax_incar and md_incar respectively. Use relax_kpt and md_kpt for the relative path for KPT files of relaxation and MD simulations. They two can be omitted if kspacing (in unit of 1/Bohr) or gamma_only has been set in corresponding INPUT files. If from_poscar is set to false, you have to specify atom_masses in the same order as elements.