Fleur Spin-Spiral Dispersion Converge workchain

  • Current version: 0.2.0

  • Class: FleurSSDispConvWorkChain

  • String to pass to the WorkflowFactory(): fleur.ssdisp_conv

  • Workflow type: Scientific workchain, self-consistent subgroup

  • Aim: Calculate spin-spiral energy dispersion over given q-points converging all the q_points.

Import Example:

from aiida_fleur.workflows.ssdisp_conv import FleurSSDispConvWorkChain
#or
WorkflowFactory('fleur.ssdisp_conv')

Description/Purpose

This workchain calculates spin spiral energy dispersion over a given set of q-points. Resulting energies do not contain terms, corresponding to DMI energies. To take into account DMI, see the Fleur Dzyaloshinskii–Moriya Interaction energy workchain documentation.

In this workchain the force-theorem is employed which means the workchain converges a reference charge density first and then submits a single FleurCalculation with a <forceTheorem> tag. However, it is possible to specify inputs to use external pre-converged charge density to use it as a reference.

The task of the workchain us to calculate the energy difference between two or several structures having a different magnetisation profile:

../../_images/ssdisp_energies.png

To do this, the workchain employs the force theorem approach:

../../_images/ssdisp_conv.png

Input nodes

The FleurSSDispWorkChain employs exposed feature of the AiiDA, thus inputs for the nested SCF workchain should be passed in the namespace scf.

name

type

description

required

scf

namespace

inputs for nested SCF WorkChain

yes

wf_parameters

Dict

Settings of the workchain

no

Workchain parameters and its defaults

wf_parameters

wf_parameters: Dict - Settings of the workflow behavior. All possible keys and their defaults are listed below:

# -*- coding: utf-8 -*-
'beta': {'all': 1.57079},                   # see the description below
'q_vectors': {'label': [0.0, 0.0, 0.0],     # sets q_points to calculate
              'label2': [0.125, 0.0, 0.0]
              }

beta is a python dictionary containing a key: value pairs. Each pair sets beta parameter in an inp.xml file. key specifies the atom label to change, key equal to ‘all’ sets all atoms groups. For example,

'beta' : {'222' : 1.57079}

changes

<atomGroup species="Fe-1">
  <filmPos label="                 222">.0000000000 .0000000000 -11.4075100502</filmPos>
  <force calculate="T" relaxXYZ="TTT"/>
  <nocoParams l_relax="F" alpha=".00000000" beta="0.00000" b_cons_x=".00000000" b_cons_y=".00000000"/>
</atomGroup>

to:

<atomGroup species="Fe-1">
  <filmPos label="                 222">.0000000000 .0000000000 -11.4075100502</filmPos>
  <force calculate="T" relaxXYZ="TTT"/>
  <nocoParams l_relax="F" alpha=".00000000" beta="1.57079" b_cons_x=".00000000" b_cons_y=".00000000"/>
</atomGroup>

Note

beta actually sets a beta parameter for a whole atomGroup. It can be that the atomGroup correspond to several atoms and beta switches sets beta for atoms that was not intended to change. You must be careful and make sure that several atoms do not correspond to a given specie.

q_vectors is a python dictionary (key: value pairs). The key can be any string which sets a label of the q-vector. value must be a list of 3 values: $$q_x, q_y, q_z$$.

Output nodes

  • out: Dict - Information of workflow results like success, last result node, list with convergence behavior

    {
    "energies": {
        "label": 0.0,
        "label2": 0.014235119451769
    },
    "energy_units": "eV",
    "errors": [],
    "failed_labels": [],
    "info": [],
    "q_vectors": {
        "label": [
            0.0,
            0.0,
            0.0
        ],
        "label2": [
            0.125,
            0.0,
            0.0
        ]
    },
    "warnings": [],
    "workflow_name": "FleurSSDispConvWorkChain",
    "workflow_version": "0.1.0"
}

    Resulting Spin Spiral energies are listed according to given labels.

Layout

SSDisp converge always starts with a structure and a list of q-vectors to calculate. There is no way to continue from pre-converged charge density.

Error handling

A list of implemented exit codes:

Code

Meaning

230

Invalid workchain parameters

340

Convergence SSDisp calculation failed for all q-vectors

341

Convergence SSDisp calculation failed for some q-vectors

Example usage

# -*- coding: utf-8 -*-
from aiida.orm import load_node, Dict
from aiida.engine import submit

from aiida_fleur.workflows.ssdisp_conv import FleurSSDispConvWorkChain

fleur_code = load_node(FLEUR_PK)
inpgen_code = load_node(INPGEN_PK)
structure = load_node(STRUCTURE_PK)

wf_para = Dict(dict={'beta': {'all': 1.57079},
                     'q_vectors': {'label': [0.0, 0.0, 0.0],
                                   'label2': [0.125, 0.0, 0.0]
                                   }
                     })


options = Dict(dict={'resources': {'num_machines': 1, 'num_mpiprocs_per_machine': 24},
                     'queue_name': 'devel',
                     'custom_scheduler_commands': '',
                     'max_wallclock_seconds':  60*60})


parameters = Dict(dict={'atom': {'element': 'Pt',
                                 'lmax': 8
                                 },
                        'atom2': {'element': 'Fe',
                                  'lmax': 8,
                                  },
                        'comp': {'kmax': 3.8,
                                 },
                        'kpt': {'div1': 20,
                                'div2': 24,
                                'div3': 1
                                }})

wf_para_scf = {'fleur_runmax': 2,
               'itmax_per_run': 120,
               'density_converged': 0.2,
               'serial': False,
               'mode': 'density'
               }

wf_para_scf = Dict(dict=wf_para_scf)

options_scf = Dict(dict={'resources': {'num_machines': 2, 'num_mpiprocs_per_machine': 24},
                         'queue_name': 'devel',
                         'custom_scheduler_commands': '',
                         'max_wallclock_seconds':  60*60})

inputs = {'scf': {'wf_parameters': wf_para_scf,
                  'structure': structure,
                  'calc_parameters': parameters,
                  'options': options_scf,
                  'inpgen': inpgen_code,
                  'fleur': fleur_code
                  },
          'wf_parameters': wf_para,
          }


res = submit(FleurSSDispConvWorkChain, **inputs)