BaseGruneisenMaker

class atomate2.common.flows.gruneisen.BaseGruneisenMaker(name='Gruneisen', bulk_relax_maker=None, code=None, const_vol_relax_maker=None, kpath_scheme='seekpath', phonon_maker=None, perc_vol=0.01, mesh=7000, compute_gruneisen_param_kwargs=<factory>, symprec=0.001)[source]

Bases: Maker, ABC

Maker to calculate Grueneisen parameters with DFT/force field code and Phonopy.

Calculate Grueneisen parameters by a finite volume change approach based on harmonic phonons. Initially, a tight structural relaxation is performed to obtain a structure without forces on the atoms. The optimized structure (ground state) is further expanded and shrunk by 1 % of its volume. Subsequently, supercells with one displaced atom are generated for all the three structures (ground state, expanded and shrunk volume) and accurate forces are computed for these structures. With the help of phonopy, these forces are then converted into a dynamical matrix. This dynamical matrix of three structures is then used as an input for the phonopy Grueneisen API to compute Grueneisen parameters.

Parameters:

  • name (str) – Name of the flows produced by this maker.

  • bulk_relax_maker (.ForceFieldRelaxMaker, .BaseAimsMaker, .BaseVaspMaker, or None) – A maker to perform an initial tight relaxation on the bulk.

  • code (str) – determines the dft or force field code.

  • const_vol_relax_maker (.ForceFieldRelaxMaker, .BaseAimsMaker,) – .BaseVaspMaker, or None. A maker to perform a tight relaxation on the expanded and shrunk structures at constant volume.

  • kpath_scheme (str) – scheme to generate kpoints. Please be aware that you can only use seekpath with any kind of cell Otherwise, please use the standard primitive structure Available schemes are: “seekpath”, “hinuma”, “setyawan_curtarolo”, “latimer_munro”. “seekpath” and “hinuma” are the same definition but seekpath can be used with any kind of unit cell as it relies on phonopy to handle the relationship to the primitive cell and not pymatgen

  • mesh (tuple or float) – Mesh numbers along a, b, c axes used for Grueneisen parameter computation. Or an int or float to indicate a kpoint density.

  • phonon_maker (.BasePhononMaker) – PhononMaker to run the phonon workflow.

  • perc_vol (float) – Percent volume to shrink and expand ground state structure

  • compute_gruneisen_param_kwargs (dict) – Keyword arguments passed to compute_gruneisen_param.

  • symprec (float) – Symmetry precision for symmetry checks and phonon runs.

make(structure, prev_dir=None)[source]

Optimizes structure and runs phonon computations.

Phonon computations are run for ground state, expanded and shrunk volume structures. Then, Grueneisen parameters are computed from this three phonon runs.

Parameters:

  • structure (Structure) – A pymatgen structure object. Please start with a structure that is nearly fully optimized as the internal optimizers have very strict settings!

  • prev_dir (str or Path or None) – A previous calculation directory to use for copying outputs.

Return type:

Flow

abstract property prev_calc_dir_argname: str | None

Name of argument informing static maker of previous calculation directory.

As this differs between different DFT codes (e.g., VASP, CP2K), it has been left as a property to be implemented by the inheriting class.

Note: this is only applicable if a relax_maker is specified; i.e., two calculations are performed for each ordering (relax -> static)