Socorro

Official Resources

• Repository: https://github.com/sandialabs/socorro (Archived)
• License: GNU General Public License (GPL)
• Status: Legacy / Archived

Overview

Socorro is a locally-basis-free, plane-wave Density Functional Theory (DFT) code developed at Sandia National Laboratories. It was engineered for extreme scalability on massively parallel supercomputers. While primary development has ceased, it remains a valuable reference for scalable algorithms, particularly for exact-exchange calculations. It includes Time-Dependent DFT (TDDFT) capabilities for excited states.

Scientific domain: Materials science, electronic structure, large-scale systems Target user community: HPC researchers, algorithm developers, legacy project support

Theoretical Methods

• Kohn-Sham DFT: Plane-wave basis set implementation
• TDDFT: Time-dependent density functional theory for excitations
• Exact Exchange: Novel algorithms for efficient Fock exchange construction
• Pseudopotentials: Norm-conserving and Projector Augmented Wave (PAW) support

Capabilities

• Massive Scalability: Demonstrated near-ideal scaling up to ~73,000 cores
• Hybrid Functionals: Efficient implementation of exact exchange
• Spin Polarization: Collinear spin support
• Modern Hardware: Support for OpenMP threading and Intel libraries

Inputs & Outputs

• Input formats: Fortran-style input files/namelists
• Output data types:
  • Electronic energies and forces
  • Charge densities
  • Wavefunctions
  • TDDFT spectra (absorption)

Performance Characteristics

• Scaling: Exceptional strong scaling for large systems (e.g., gold supercells)
• Parallelism: MPI + OpenMP hybrid
• Efficiency: Outperformed commercial codes of its era in core scaling for hybrid functionals

Computational Cost

• High Core Count: Designed to utilize large partitions of supercomputers efficiently.
• Memory: Distributed memory model allows for large system sizes.

Limitations & Known Constraints

• Development: Code is archived and no longer actively maintained.
• Support: No official user support; relies on legacy documentation.
• Interface: Less user-friendly than modern Python-driven codes.

Comparison with Other Codes

• vs VASP/QE: Socorro focuses purely on scalability for specific large problems; VASP/QE are general-purpose with larger ecosystems.
• vs Conquest: Both focus on large systems, but Socorro uses standard plane-waves with efficient parallelization rather than O(N) basis sets.

Citations

• Primary: "Socorro: a DFT code for the future?" (Sandia Reports/J. Comp. Phys.)