Lobster

Official Resources

• Homepage: https://www.cohp.de/
• Documentation: http://www.cohp.de/
• Source Repository: Proprietary (free for academic use)
• License: Free for academic research (registration required)

Overview

Lobster (Local Orbital Basis Suite Towards Electronic-Structure Reconstruction) is a program for chemical bonding analysis based on projecting plane-wave DFT calculations onto a local basis. It enables the calculation of Crystal Orbital Hamilton Populations (COHP), Crystal Orbital Overlap Populations (COOP), and related bonding descriptors from PAW or pseudopotential calculations.

Scientific domain: Chemical bonding analysis, electron localization, orbital interactions
Target user community: Chemists and materials scientists studying bonding in solids

Theoretical Methods

• Projection from plane-wave basis to local atomic orbitals
• Crystal Orbital Hamilton Population (COHP)
• Crystal Orbital Overlap Population (COOP)
• Integrated COHP (ICOHP) for bond strength quantification
• Projected density of states (pDOS)
• Charge analysis (Mulliken, Löwdin)
• Fat band analysis

Capabilities (CRITICAL)

• COHP analysis for chemical bonding characterization
• COOP analysis for orbital overlap
• ICOHP calculation for quantitative bond strengths
• Projected density of states onto atomic orbitals
• Atom-resolved and orbital-resolved analysis
• Bonding/antibonding character identification
• Charge partitioning (Mulliken, Löwdin populations)
• Fat band structures with orbital character
• Automatic neighbor list generation for bonding pairs
• Interface to VASP (primary)
• Interface to ABINIT
• Interface to Quantum ESPRESSO
• Batch processing capabilities
• Visualization-ready output formats

Sources: Official Lobster website, publications, cited in 7/7 source lists

Key Strengths

Chemical Bonding Insight:

• COHP/COOP analysis
• Quantitative ICOHP values
• Bonding/antibonding decomposition
• Orbital-resolved analysis

Multi-Code Support:

• VASP (primary)
• Quantum ESPRESSO
• ABINIT support
• Consistent methodology

Production Ready:

• Automated neighbor detection
• Batch processing
• LobsterPy integration
• Materials Project use

Inputs & Outputs

• Input formats:

  • POSCAR (VASP structure)
  • POTCAR (PAW information)
  • WAVECAR (VASP wavefunctions)
  • DOSCAR.lobster (optional)
  • lobsterin (Lobster input file)

• Output data types:

  • COHPCAR.lobster (COHP data)
  • COOPCAR.lobster (COOP data)
  • DOSCAR.lobster (projected DOS)
  • CHARGE.lobster (charge analysis)
  • ICOHPLIST.lobster (integrated COHP values)
  • Orbital-resolved outputs
  • Visualization files

Interfaces & Ecosystem

• DFT code interfaces (verified):

  • VASP - primary and most complete interface
  • Quantum ESPRESSO - supported
  • ABINIT - supported

• Post-processing tools:

  • LobsterPy - Python package for automated analysis
  • wxDragon - visualization tool for COHP
  • Built-in plotting utilities

• Framework integrations:

  • pymatgen - can read Lobster outputs
  • Materials Project - uses Lobster for bonding analysis
  • Automated workflows via Python scripts

Limitations & Known Constraints

• Projection quality: Results depend on quality of projection; may not be unique
• Basis completeness: Local basis may not span full Hilbert space
• PAW limitations: Some approximations in PAW reconstruction
• Interpretability: COHP/COOP interpretation requires chemical intuition
• Code availability: Free but requires registration; not fully open-source
• DFT dependency: Inherits all limitations of underlying DFT calculation
• Large systems: Memory and computational cost increase with system size
• k-point sampling: Requires adequate k-point mesh from DFT
• Documentation: Limited compared to major DFT codes
• Atomic basis choice: Results can depend on choice of local basis functions

Comparison with Other Tools

• vs Bader: COHP bonding analysis, Bader charge partitioning
• vs DDEC: Different analysis perspectives
• vs Critic2: Lobster orbital-based, Critic2 density-based
• Unique strength: COHP/COOP for solid-state bonding

Best Practices

• Use adequate k-point sampling in DFT
• Check projection quality (spillings)
• Compare ICOHP values for bond ranking
• Validate with known compounds

Verification & Sources

Primary sources:

1. Official website: https://www.cohp.de/
2. S. Maintz et al., J. Comput. Chem. 37, 1030 (2016) - Lobster paper
3. V. L. Deringer et al., J. Phys. Chem. A 115, 5461 (2011) - COHP analysis
4. R. Dronskowski and P. E. Blöchl, J. Phys. Chem. 97, 8617 (1993) - COHP method

Secondary sources:

1. VASP wiki on Lobster interface
2. Materials Project documentation on bonding analysis
3. LobsterPy documentation
4. Confirmed in 7/7 source lists (claude, g, gr, k, m, q, z)

Confidence: CONFIRMED - Appears in all 7 independent source lists

Verification status: ✅ VERIFIED

• Official homepage: ACCESSIBLE
• Documentation: ACCESSIBLE (requires registration for full access)
• Community support: Active (email support, user group)
• Academic citations: >300 (main paper)
• Widely used: Standard tool for bonding analysis in materials science