VASP is a complex package for performing ab-initio quantum-mechanical molecular dynamics (MD) simulations using pseudopotentials or the projector-augmented wave method and a plane wave basis set. The approach implemented in VASP is based on the (finite-temperature) local-density approximation with the free energy as variational quantity and an exact evaluation of the instantaneous electronic ground state at each MD time step. VASP uses efficient matrix diagonalization schemes and an efficient Pulay/Broyden charge density mixing. These techniques avoid all problems possibly occurring in the original Car-Parrinello method, which is based on the simultaneous integration of electronic and ionic equations of motion. The interaction between ions and electrons is described by ultra-soft Vanderbilt pseudopotentials (US-PP) or by the projector-augmented wave (PAW) method. US-PP (and the PAW method) allow for a considerable reduction of the number of plane-waves per atom for transition metals and first row elements. Forces and the full stress tensor can be calculated with VASP and used to relax atoms into their instantaneous ground-state.
ABINIT is a package whose main program allows one to find the total energy, charge density and electronic structure of systems made of electrons and nuclei (molecules and periodic solids) within Density Functional Theory (DFT), using pseudopotentials and a planewave or wavelet basis.
Aces (Advanced Concepts in Electronic Structure Theory) is an ab initio computational chemistry package for performing high-level quantum chemical ab initio calculations. Its major strength is the accurate calculation of atomic and molecular energies as well as properties using many-body techniques such as Many-Body Perturbation theory (MBPT) and, in particular coupled cluster techniques to treat electron correlation.
Amsterdam Density Functional (ADF) is particularly strong in understanding and predicting structure, reactivity and spectra of molecules. ADF is frequently used for studying transition metal complexes and molecules with heavy atoms, since all elements in the periodic table can be modeled accurately and efficiently with the ZORA relativistic approach and all-electron basis sets. ADF offers unique capabilities to predict molecular properties of organic electronics materials. ADF is easy to use with parallel binaries, integrated GUI, and supported by experts with decades of experience.
BigDFT is a DFT massively parallel electronic structure code using a wavelet basis set. Wavelets form a real space basis set distributed on an adaptive mesh.
CP2K is a quantum chemistry and solid state physics software package that can perform atomistic simulations of solid state, liquid, molecular, periodic, material, crystal and biological systems. CP2K provides a general framework for different modeling methods such as DFT using the mixed Gaussian and plane waves approaches GPW and GAPW.
The General Atomic and Molecular Electronic Structure System (GAMESS) is a general ab initio molecular quantum chemistry package. GAMESS can perform a number of general computational chemistry calculations, including Hartree-Fock, density functional theory (DFT), generalized valence bond (GVB), and multi-configurational self-consistent field (MCSCF).
Gaussian is the latest in the Gaussian series of electronic structure programs. Gaussian is used by chemists, chemical engineers, biochemists, physicists and others for research in established and emerging areas of chemical interest. Starting from the basic laws of quantum mechanics, Gaussian predicts the energies, molecular structures, and vibrational frequencies of molecular systems, along with numerous molecular properties derived from these basic computation types. It can be used to study molecules and reactions under a wide range of conditions, including both stable species and compounds which are difficult or impossible to observe experimentally such as short-lived intermediates and transition structures.
LSDalton is a linear-scaling HF and DFT code suitable for large molecular systems, now also with some CCSD capabilities.
NWChem is an ab initio computational chemistry software package with built-in support for quantum chemical and molecular dynamics capabilities. NWChem is developed and maintained by the Molecular Sciences Software group at the Pacific Northwest National Laboratory (PNNL) and aims to be scalable both in its ability to treat large problems efficiently as well as in its usage of available parallel computing resources.
Octopus is a scientific program aimed at the ab initio virtual experimentation on a hopefully ever-increasing range of system types. Electrons are described quantum-mechanically within density-functional theory (DFT), in its time-dependent form (TDDFT) when doing simulations in time. Nuclei are described classically as point particles. Electron-nucleus interaction is described within the pseudopotential approximation.
Q-Chem is a comprehensive ab initio quantum chemistry package for accurate predictions of molecular structures, reactivities, and vibrational, electronic and NMR spectra.
Quantum ESPRESSO (opEn-Source Package for Research in Electronic Structure, Simulation, and Optimization) is an integrated suite of open-source computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves and pseudopotentials.
TeraChem is general purpose quantum chemistry software designed to run on NVIDIA GPU architectures under a 64-bit Linux operating system.