CRYSTAL
A solid-state electronic-structure package using localized Gaussian basis functions for Hartree–Fock, DFT and hybrid-functional calculations.
Where it fits
Crystalline energetics, dielectric response and vibrational properties using localized bases.
Limits and practical considerations
Diffuse functions and integral thresholds need care in periodic systems; parallel editions have different entitlements.
Licensing and access
Paid proprietary licensing through CRYSTAL Solutions; platform and massively parallel extensions are licence-dependent.
Official documentation and project