Workflows

VASP Workflows

Warning

This page is a work-in-progress, as we are still developing guides for defining custom VASP workflows.

---

Available Workflows

Note

This app is meant more so for building VASP workflows, rather the providing presets. Therefore, many more VASP workflows are available in the materials_project and warren_lab apps.

relaxation.vasp.quality00
relaxation.vasp.quality01
relaxation.vasp.quality02
relaxation.vasp.quality03
relaxation.vasp.quality04
relaxation.vasp.staged
static-energy.vasp.quality04

---

Making New Workflows

VaspWorkflow base class

The VaspWorkflow class, which includes many built-in features:

basic VASP examplefull-feature VASP exampleCustom INCAR modifier

from simmate.apps.vasp.workflows.base import VaspWorkflow

class Relaxation__Vasp__MyExample1(VaspWorkflow):

    functional = "PBE"
    potcar_mappings = {"Y": "Y_sv", "C": "C"}

    _incar = dict(
        PREC="Normal",
        EDIFF=1e-4,
        ENCUT=450,
        NSW=100,
        KSPACING=0.4,
    )

from simmate.apps.vasp.workflows.base import VaspWorkflow
from simmate.apps.vasp.inputs import PBE_POTCAR_MAPPINGS
from simmate.apps.vasp.error_handlers import (
    Frozen,
    NonConverging,
    Unconverged,
    Walltime,
)


class Relaxation__Vasp__MyExample2(VaspWorkflow):

    functional = "PBE"
    potcar_mappings = PBE_POTCAR_MAPPINGS  # (1)

    _incar = dict(
        PREC="Normal",  # (2)
        EDIFF__per_atom=1e-5,  # (3)
        ENCUT=450,
        ISIF=3,
        NSW=100,
        IBRION=1,
        POTIM=0.02,
        LCHARG=False,
        LWAVE=False,
        KSPACING=0.4,
        multiple_keywords__smart_ismear={  # (4)
            "metal": dict(
                ISMEAR=1,
                SIGMA=0.06,
            ),
            "non-metal": dict(
                ISMEAR=0,
                SIGMA=0.05,
            ),
        },
        # WARNING --> see "Custom Modifier"" tab for this to work
        EXAMPLE__multiply_nsites=8,  # (5)
    )

    error_handlers = [  # (6)
        Unconverged(),
        NonConverging(),
        Frozen(),
        Walltime(),
    ]

1. You can use pre-set mapping for all elements rather than define them yourself
2. Settings that match the normal VASP input are the same for all structures regardless of composition.
3. Settings can also be set based on the input structure using built-in tags like __per_atom. Note the two underscores (__) signals that we are using a input modifier.
4. The type of smearing we use depends on if we have a metal, semiconductor, or insulator. So we need to decide this using a built-in keyword modifier named smart_ismear. Because this handles the setting of multiple INCAR values, the input begins with multiple_keywords instead of a parameter name.
5. If you want to create your own logic for an input parameter, you can do that as well. Here we are showing a new modifier named multiply_nsites. This would set the incar value of EXAMPLE=16 for structure with 2 sites (2*8=16). Note, we define how this modifer works and register it in the "Custom INCAR modifier" tab. Make sure you include this code as well.
6. These are some default error handlers to use, and there are many more error handlers available than what's shown. Note, the order of the handlers matters here. Only the first error handler triggered in this list will be used before restarting the job

If you need to add advanced logic for one of your INCAR tags, you can register a keyword_modifier to the INCAR class like so:

# STEP 1: define the logic of your modifier as a function
# Note that the function name must begin with "keyword_modifier_"
def keyword_modifier_multiply_nsites(structure, example_mod_input):
    # add your advanced logic to determine the keyword value.
    return structure.num_sites * example_mod_input

# STEP 2: register modifier with the Incar class
from simmate.apps.vasp.inputs import Incar
Incar.add_keyword_modifier(keyword_modifier_multiply_nsites)

# STEP 3: use your new modifier with any parameter you'd like
_incar = dict(
    "NSW__multiply_nsites": 2,
    "EXAMPLE__multiply_nsites": 123,
)

Danger

Make sure this code is ran BEFORE you run the workflow. Registration is reset every time a new python session starts. Therefore, we recommend keeping your modifer in the same file that you define your workflow in.

You can also use Python inheritance to borrow utilities and settings from an existing workflow:

from simmate.workflows.utilities import get_workflow

original_workflow = get_workflow("static-energy.vasp.matproj")


class StaticEnergy__Vasp__MyCustomPreset(original_workflow):

    version = "2022.07.04"

    _incar_updates = dict(
        NPAR=1,
        ENCUT=-1,
    )

---