Fleur crystal field workflow
Current version: 0.2.0
Class:
FleurCFCoeffWorkChain
String to pass to the
WorkflowFactory()
:fleur.cfcoeff
Workflow type: Scientific workchain
Aim: Calculate 4f Crystal field coefficients
Contents
Import Example:
from aiida_fleur.workflows.cfcoeff import FleurCFCoeffWorkChain
#or
WorkflowFactory('fleur.cfcoeff')
Description/Purpose
Calculates the 4f crystal field coefficients for a given structure using the method. described in C.E. Patrick, J.B. Staunton: J. Phys.: Condens. Matter 31, 305901 (2019).
This method boils down to the formula
where \(V_{lm}(r)\) is the potential of the surroundings of the 4f site and \(n_{4f}(r)\) is the spherical charge density of the 4f state. The potential is calculated using one of two options:
Calculate the potential of an analogue structure, where the 4f atom is replaced by a ytrrium atom.
Calculate the potential from the system including the 4f atom directly.
This is done by first calculating the converged charge density for the 4f structure
and if used the analogue structure with the FleurScfWorkChain. Then a subsequent calculation
is done to extract the potentials/charge density. The calculation of the formula above
is done after with the CFCalculation
tool in masci-tools.
Input nodes
The table below shows all the possible input nodes of the SCF workchain.
name |
type |
description |
required |
---|---|---|---|
scf |
namespace |
Inputs for the SCF workchain including the 4f atom |
no |
orbcontrol |
namespace |
Inputs for the Orbcontrol workchain including the 4f atom |
no |
scf_rare_earth_analogue |
namespace |
Inputs for the SCF workchain with the 4f atom replaced with the analogue |
no |
wf_parameters |
Settings of the workchain |
no |
One of the scf or orbcontrol input nodes is required.
Workchain parameters and its defaults
wf_parameters
:Dict
- Settings of the workflow behavior. All possible keys and their defaults are listed below:# -*- coding: utf-8 -*- 'element': '', # detemines for which element to calculate # the crystal field coefficients 'rare_earth_analogue': True, # True if analogue calculation should be used 'analogue_element': 'Y', # Which element to use for the analogue structure 'replace_all': True, # Whether to replace all atoms for the analogue in one structure 'soc_off': True, # if True the socscale is set to 0.0 for the 4f site 'convert_to_stevens': True # if True the coefficients are converted to the stevens convention # A_lm<r^l>
Returns nodes
The table below shows all the possible output nodes of the SCF workchain.
name |
type |
comment |
---|---|---|
output_cfcoeff_wc_para |
results of the workchain |
|
output_cfcoeff_wc_potentials |
XyData with the calculated potentials |
|
output_cfcoeff_wc_charge_densities |
XyData with the calculated charge densities |
Layout
TODO
Error handling
In case of failure the SCF WorkChain should throw one of the exit codes:
Exit code |
Reason |
---|---|
230 |
Invalid workchain parameters |
231 |
Invalid input configuration |
235 |
Input file modification failed. |
236 |
Input file was corrupted after modifications |
345 |
SCF workchain failed |
451 |
Orbcontrol workchain failed |
452 |
FleurBaseWorkChain for CF calculation failed |
If your workchain crashes and stops in Excepted state, please open a new issue on the Github page and describe the details of the failure.
Plot_fleur visualization
TODO
Database Node graph
TODO
Example usage
TODO