RSPt Extractor

Version: 0.4.0 Author: Anders Bergman

Overview

rspt-extractor is a Python package for extracting and processing data from RSPt calculations. It reads exchange data from multiple input files, processes the data, and combines the results. The package also provides methods to extract and print information from an SCF (Self-consistent field) run.

This tool is specifically designed to help researchers working with RSPt and related calculations in condensed matter physics.

Features

• Exchange Data Extraction: Extracts exchange data from multiple files and processes it.
• Data Masking: Applies masks to filter the data based on user-specified criteria.
• SCF Run Information: Extracts and prints key details from an SCF calculation.

Installation

To install rspt-extractor, use the following command after cloning the repository:

pip install -e .

Usage

The classes included in the package can be customized to your preferred directory structure with the suitable flags. Files needed from an RSPt calculation are the following:

• data: RSPt structure input file. Needed for positions of atoms.
• out.scf (arbitrary name): Terminal output from RSPt SCF calculation. Needed for magnetic moments.
• out.jij (arbitrary name): Terminal output from RSPt Jij calculation. Needed for extraction of exchange interactions and neighbour information.

To allow for flexible naming and placing of these files, all inputs are given as flags to the parser. Thus, assuming the naming convention above, and a single Jij output file, the syntax would be

rspt-parser --data data --scf out.scf --exchange out.jij

to extract the calculated exchange interactions.

Flags

While the package can be customized to your own needs, the default script rspt-extractor comes with a number of flags to allow more user control. The flags are visible by rspt-extractor --help and are currently as follows

RSPt exchange extraction tool

options:
  -h, --help            show this help message and exit
  -d DATA, --data DATA  FILE_NAME for RSPt input data
  -s SCF, --scf SCF     FILE_NAME for RSPt SCF output data
  -e FILE_NAME [FILE_NAME ...], --exchange FILE_NAME [FILE_NAME ...]
                        Run exchange workflow for the given FILE_NAMEs
  --rx FILE_NAME [FILE_NAME ...]
                        Input files for relativistic exchange workflow (x-direction)
  --ry FILE_NAME [FILE_NAME ...]
                        Input files for relativistic exchange workflow (y-direction)
  --rz FILE_NAME [FILE_NAME ...]
                        Input files for relativistic exchange workflow (z-direction)
  -m MAPTYPE, --maptype MAPTYPE
                        Output maptype: (C)artesian, (D)irect or maptype (3)
  -a ATOMS [ATOMS ...], --atoms ATOMS [ATOMS ...]
                        List of atoms to extract exchange interactions for
  -t THRESHOLD, --threshold THRESHOLD
                        Threshold for moment magnitudes. Default is 0.0
  -c CUTOFF, --cutoff CUTOFF
                        Radius for excange interaction cutoff

Included examples

FePt

An example for relativistic exchange interaction extraction can be found in the folder examples/FePt. For relativistic interactions, three different calculations with different spin axes are needed. In this example the calculations are grouped within the following folder structure

├── FePt
│   ├── spin-001
│   ├── spin-010
│   └── spin-100

with the output files from both SCF and Jij calculations available in each subfolder. To extract the relativistic exchange interactions the syntax for this example should be

rspt-parser --scf spin-001/out-scf --data spin-001/data --rx spin-100/out-? --ry spin-010/out-? --rz spin-001/out-?

where --rx, --ry, and --rz controls where the Jij output files are fund. Notice the wild-carding since there are several Jij output files in each directory.

NOTE: The relativistic workflow is not guaranteed to work due to the risk of uncontrolled reshuffeling of atoms between the different spin-axis calculations. A fix for this is pending for the RSPt code.

YFe2

For scalar exchange interactions, an example can be found in the examples/YFe2 folder. Here the file structure is as follows:

YFe2
├── Jij-01
│   └── out
├── Jij-02
│   └── out
├── Jij-03
│   └── out
├── Jij-04
│   └── out
├── Jij-05
│   └── out
├── Jij-06
│   └── out
├── data
└── out_last

i.e. each atom has its Jij output files in a separate directory while the SCF output file (here out_last) and the data file are located in the root folder. For scalar exchange, the relevant flag is --exchange and the extraction of exchange parameters for this system would then be

rspt-parser --data data --scf out_last --exchange Jij*/out

Additional flags

Thresholding the output can be done by either moment magnitude or cutoff radius. To only extract the Fe atoms in the YFe2 example above we can add the --threshold 0.5 which will filter out all atoms with a magnetic moment lower than $0.5 \mu_B$. To enforce a cutoff radius, the flag --cutoff 3.0 can be included to truncate the exchange interactions to only include interactions within $3.0$ lattice parameters. Example:

rspt-parser --data data --scf out_last --exchange Jij*/out --cutoff 3.0 --threshold 0.5

Output files

After a successful run, rspt-parser should create the following set of files:

• inpsd.dat: A template UppASD input file containing minimal needed information
• posfile: Positions in the unit cells for the included atoms
• momfile: Moment magnitudes for the included atoms in the unit cell
• jfile: Scalar representation of Jij exchange interactions

For relativistic workflows the additional files are also included:

• dmfile: Dzyaloshinskii-Moriya interactions (DMI) in vector form
• cfile: Symmetric anisotropic exchange interactions (SAI) (non-diagonal only)
• jfile.tensor: Full tensor containing Jij, DMI, and SAI for all interactions.

All files follows the conventions for UppASD inputs.