CHARMM directly interfaces with the following packages:
- GAMESS-US / quantum chemistry
- GAMESS-UK / quantum chemistry
- Q-Chem / quantum chemistry
- Gaussian / quantum chemistry
- CADPAC / quantum chemistry
- SCC-DFTB / quantum chemistry
- SQUANTM / quantum chemistry
- MND097 / quantum chemistry
- Turbomole / quantum chemistry
- APBS / Poisson-Boltzmann solver
- FFTW / fast Fourier transform
- POLYRATE / reaction kinetics
- OpenMM / GPU performance
These packages have to be obtained and installed separately.