DensityTool

Official Resources

• Source Repository: https://github.com/llodeiro/DensityTool
• Documentation: Included in repository
• License: Open source

Overview

DensityTool is a FORTRAN post-processing program for space- and spin-resolved density of states from VASP. It provides detailed spatial and spin decomposition of the DOS, enabling atom-, shell-, and orbital-projected DOS analysis beyond standard VASP output.

Scientific domain: DOS analysis, spin-resolved density of states, VASP post-processing
Target user community: Researchers needing detailed spatial and spin decomposition of DOS from VASP calculations

Theoretical Methods

• Space-resolved density of states
• Spin-resolved DOS analysis
• Atom-projected DOS
• Shell-projected DOS (s, p, d, f)
• Orbital-projected DOS
• VASP PROCAR/DOSCAR parsing

Capabilities (CRITICAL)

• Space-resolved DOS calculation
• Spin-resolved DOS decomposition
• Atom-projected DOS
• Shell (s, p, d, f) projected DOS
• Orbital-projected DOS
• VASP output parsing
• Custom region DOS integration

Sources: GitHub repository, Comput. Phys. Commun. 277, 108384 (2022)

Key Strengths

Space-Resolved DOS:

• DOS in custom spatial regions
• Not limited to atomic spheres
• Integration over user-defined volumes
• Unique spatial decomposition

Spin Resolution:

• Full spin-resolved analysis
• Up/down spin channels
• Spin density decomposition
• Magnetic DOS analysis

Beyond Standard VASP:

• More detailed than standard PROCAR
• Custom spatial regions
• Shell and orbital decomposition
• Flexible output

Inputs & Outputs

• Input formats:

  • VASP PROCAR
  • VASP DOSCAR
  • Spatial region definitions

• Output data types:

  • Space-resolved DOS
  • Spin-resolved DOS
  • Atom/shell/orbital projected DOS
  • Custom region DOS

Interfaces & Ecosystem

• VASP: Primary DFT backend
• FORTRAN: Core computation

Performance Characteristics

• Speed: Fast (post-processing)
• Accuracy: VASP-level
• System size: Limited by PROCAR size
• Memory: Moderate

Computational Cost

• DOS analysis: Seconds to minutes
• VASP pre-requisite: Hours (separate)
• Typical: Very efficient

Limitations & Known Constraints

• VASP only: No QE or other code support
• FORTRAN: Compilation required
• PROCAR dependency: Requires LORBIT=11
• Limited documentation: Could be more extensive

Comparison with Other Codes

• vs pyprocar: DensityTool has space-resolved DOS, pyprocar is more general
• vs VASPKIT: DensityTool has spatial decomposition, VASPKIT is broader
• vs sumo: DensityTool has unique space-resolved DOS
• Unique strength: Space-resolved and spin-resolved DOS decomposition from VASP, custom spatial regions

Application Areas

Magnetic Materials:

• Spin-resolved DOS
• Magnetic moment analysis
• Exchange splitting
• Spin-polarized surface states

Surface Science:

• Surface-localized DOS
• Interface state analysis
• Vacuum region DOS
• Spatial DOS mapping

Defect Analysis:

• Defect state localization
• Spatial extent of defect states
• Spin polarization at defects
• Impurity state decomposition

Best Practices

VASP Setup:

• Set LORBIT=11 for PROCAR
• Use sufficient k-points for DOS
• Include spin polarization if needed
• Use appropriate RWIGS

Spatial Analysis:

• Define meaningful spatial regions
• Test convergence with grid
• Compare with atomic sphere results
• Validate against total DOS

Community and Support

• Open source on GitHub
• Published in Comput. Phys. Commun.
• Research code
• Limited documentation

Verification & Sources

Primary sources:

1. GitHub: https://github.com/llodeiro/DensityTool
2. L. Lodeiro and T. Rauch, Comput. Phys. Commun. 277, 108384 (2022)

Confidence: VERIFIED

Verification status: ✅ VERIFIED

• Source code: ACCESSIBLE (GitHub)
• Documentation: Included in repository
• Published methodology: Comput. Phys. Commun.
• Specialized strength: Space-resolved and spin-resolved DOS decomposition from VASP, custom spatial regions