Comparing DOS with PyProcar

Overview

The pyprocar.dosplot() function is a powerful tool for visualizing density of states (DOS). One of its key features is that it returns matplotlib Figure and Axes objects when show=False, which enables advanced plotting capabilities including comparing multiple DOS curves on the same plot.

What dosplot returns

When called with show=False, dosplot() returns:

  • fig: A matplotlib Figure object containing the entire plot

  • ax: A matplotlib Axes object representing the plotting area

Method for comparing DOS

To compare DOS from different sources, calculations, or components:

  1. First call: Use dosplot() with show=False to generate the initial DOS and capture the fig and ax objects

  2. Subsequent calls: Pass the ax object to additional dosplot() calls using the ax parameter

  3. Final display: The last call should have show=True to display the combined plot

This approach allows you to overlay multiple DOS from:

  • Different DFT codes (like VASP and Quantum Espresso)

  • Different spin channels (spin-up vs spin-down)

  • Different orbital projections (s, p, d, f orbitals)

  • Different atoms or species in the same system

  • Different calculation parameters (k-points, functionals, etc.)

Benefits of DOS Comparison

Comparing DOS helps you:

  • Validate calculations across different codes

  • Understand electronic structure by comparing different components

  • Analyze magnetic properties by comparing spin channels

  • Study orbital contributions from different atoms or orbital types

  • Examine convergence with different computational parameters

1. Setup and Data Loading

First, we’ll import the necessary libraries and download example data. We’ll use both spin-polarized and non-spin-polarized data to demonstrate various DOS comparison techniques.

[ ]:

# Import required libraries
from pathlib import Path
import pyprocar

CURRENT_DIR = Path(".").resolve()

# Download both spin-polarized and non-spin-polarized data
SPIN_POL_PATH = "data/examples/dos/spin-polarized"
NON_SPIN_POL_PATH = "data/examples/dos/non-spin-polarized"

pyprocar.download_from_hf(relpath=SPIN_POL_PATH, output_path=CURRENT_DIR)
pyprocar.download_from_hf(relpath=NON_SPIN_POL_PATH, output_path=CURRENT_DIR)

SPIN_POL_DATA_DIR = CURRENT_DIR / SPIN_POL_PATH
NON_SPIN_POL_DATA_DIR = CURRENT_DIR / NON_SPIN_POL_PATH

print(f"Spin-polarized data: {SPIN_POL_DATA_DIR}")
print(f"Non-spin-polarized data: {NON_SPIN_POL_DATA_DIR}")
print("✅ Data ready for DOS comparison examples!")

Data already exists at C:\Users\lllang\Desktop\notebooks\Notebook\01 - Projects\Pyprocar\pyprocar\examples\01-dos\data\examples\01-dos\spin-polarized
Data already exists at C:\Users\lllang\Desktop\notebooks\Notebook\01 - Projects\Pyprocar\pyprocar\examples\01-dos\data\examples\01-dos\non-spin-polarized
Spin-polarized data: C:\Users\lllang\Desktop\notebooks\Notebook\01 - Projects\Pyprocar\pyprocar\examples\01-dos\data\examples\01-dos\spin-polarized
Non-spin-polarized data: C:\Users\lllang\Desktop\notebooks\Notebook\01 - Projects\Pyprocar\pyprocar\examples\01-dos\data\examples\01-dos\non-spin-polarized
✅ Data ready for DOS comparison examples!

2. Basic DOS Comparison: Spin Channels

Now we’ll demonstrate the fundamental DOS comparison technique by comparing spin-up and spin-down channels from the same calculation:

  1. Step 1: Plot the spin-up DOS with show=False to capture the fig and ax objects

  2. Step 2: Plot the spin-down DOS using the same ax object with show=True to display the combined result

This creates a side-by-side comparison of spin channels, which is essential for understanding magnetic properties.

[2]:

# Step 1: Plot spin-up DOS and capture fig, ax objects
fig, ax = pyprocar.dosplot(
    code="vasp",
    dirname=SPIN_POL_DATA_DIR,
    mode="plain",
    fermi=5.3017,
    elimit=[-6, 4],
    spins=[0],  # Spin-up channel
    color="blue",
    show=False,  # Don't show yet, capture the axes
)

# Step 2: Plot spin-down DOS on the same axes
pyprocar.dosplot(
    code="vasp",
    dirname=SPIN_POL_DATA_DIR,
    mode="plain",
    fermi=5.3017,
    elimit=[-6, 4],
    spins=[1],  # Spin-down channel
    color="red",
    ax=ax,  # Use the same axes from spin-up plot
    show=True,  # Show the combined plot
)

print("🧲 Spin comparison: Blue = spin-up, Red = spin-down")

If you want more detailed logs, set verbose to 2 or more
____________________________________________________________________________________________________
 ____        ____
|  _ \ _   _|  _ \ _ __ ___   ___ __ _ _ __
| |_) | | | | |_) | '__/ _ \ / __/ _` | '__|
|  __/| |_| |  __/| | | (_) | (_| (_| | |
|_|    \__, |_|   |_|  \___/ \___\__,_|_|
       |___/
A Python library for electronic structure pre/post-processing.

Version 6.4.6 created on Mar 6th, 2025

Please cite:
- Uthpala Herath, Pedram Tavadze, Xu He, Eric Bousquet, Sobhit Singh, Francisco Muñoz and Aldo Romero.,
  PyProcar: A Python library for electronic structure pre/post-processing.,
  Computer Physics Communications 251, 107080 (2020).

- L. Lang, P. Tavadze, A. Tellez, E. Bousquet, H. Xu, F. Muñoz, N. Vasquez, U. Herath, and A. H. Romero,
  Expanding PyProcar for new features, maintainability, and reliability.,
  Computer Physics Communications 297, 109063 (2024).

Developers:
- Francisco Muñoz
- Aldo Romero
- Sobhit Singh
- Uthpala Herath
- Pedram Tavadze
- Eric Bousquet
- Xu He
- Reese Boucher
- Logan Lang
- Freddy Farah

____________________________________________________________________________________________________

            There are additional plot options that are defined in a configuration file.
            You can change these configurations by passing the keyword argument to the function
            To print a list of plot options set print_plot_opts=True

            Here is a list modes : plain , parametric , parameteric_line , stack , stack_orbitals , stack_species , overlay , overlay_orbitals , overlay_species
____________________________________________________________________________________________________
Plotting DOS in plain mode
If you want more detailed logs, set verbose to 2 or more
____________________________________________________________________________________________________
 ____        ____
|  _ \ _   _|  _ \ _ __ ___   ___ __ _ _ __
| |_) | | | | |_) | '__/ _ \ / __/ _` | '__|
|  __/| |_| |  __/| | | (_) | (_| (_| | |
|_|    \__, |_|   |_|  \___/ \___\__,_|_|
       |___/
A Python library for electronic structure pre/post-processing.

Version 6.4.6 created on Mar 6th, 2025

Please cite:
- Uthpala Herath, Pedram Tavadze, Xu He, Eric Bousquet, Sobhit Singh, Francisco Muñoz and Aldo Romero.,
  PyProcar: A Python library for electronic structure pre/post-processing.,
  Computer Physics Communications 251, 107080 (2020).

- L. Lang, P. Tavadze, A. Tellez, E. Bousquet, H. Xu, F. Muñoz, N. Vasquez, U. Herath, and A. H. Romero,
  Expanding PyProcar for new features, maintainability, and reliability.,
  Computer Physics Communications 297, 109063 (2024).

Developers:
- Francisco Muñoz
- Aldo Romero
- Sobhit Singh
- Uthpala Herath
- Pedram Tavadze
- Eric Bousquet
- Xu He
- Reese Boucher
- Logan Lang
- Freddy Farah

____________________________________________________________________________________________________

            There are additional plot options that are defined in a configuration file.
            You can change these configurations by passing the keyword argument to the function
            To print a list of plot options set print_plot_opts=True

            Here is a list modes : plain , parametric , parameteric_line , stack , stack_orbitals , stack_species , overlay , overlay_orbitals , overlay_species
____________________________________________________________________________________________________
Plotting DOS in plain mode
../../_images/examples_01-dos_02-Comparing_DOS_4_1.png 
🧲 Spin comparison: Blue = spin-up, Red = spin-down