Semi-Empirical and Quantum Mechanics

Red - Costs money    Green - Freeware/Shareware

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Summary

ADF The Amsterdam Density Functional (ADF) package is software for first-principles electronic structure calculations.
BOSS The BOSS program is a general purpose molecular modeling system that performs molecular mechanics (MM) calculations, Metropolis Monte Carlo (MC) statistical mechanics simulations, and semiempirical AM1, PM3, and PDDG/PM3 quantum mechanics (QM) calculations.  Cost is about $1500 
Columbus COLUMBUS is a collection of programs for high-level ab initio molecular electronic structure calculations. The programs are designed primarily for extended multi-reference (MR) calculations on electronic ground and excited states of atoms and molecules.
CPMD The CPMD code is a plane wave/pseudopotential  implementation of Density Functional Theory, particularly
designed for ab-initio molecular dynamics.
Dalton Dalton QCP represents a powerful quantum chemistry program for the calculation of molecular properties with SCF, MP2, MCSCF or CC wave functions. The strengths of the program are mainly in the areas of magnetic and (frequency-dependent) electric properties, and for studies of molecular potential energy surfaces, both for static and dynamical investigations. 
DivCon DivCon is a linear-scaling semi-empirical quantum mechanical software program that carries out divide-and-conquer (D&C) methodology to study intermolecular interactions large biomolecules and ligands.  
Dirac04 Dirac is a relativistic ab inition electronic structure program.  Methods include H-F, DFT, CI, MPPT, and Coupled Cluster 
DRAGON DRAGON is a software package for the calculation of molecular descriptors (1481 descriptors).  For example, signifcant functional groups, fragment-based Polar Surface Area, logP and molar refractivity descriptors all can be calculated.
EMSL Gaussian basis set library Basis sets were obtained from the Extensible Computational Chemistry Environment Basis Set Database, Version 10/29/02, as developed and distributed by the Molecular Science Computing Facility, EMSL which is part of the PNL.
EMSL Gaussian basis set library Mirror Mirror Site for Basis sets were obtained from the Extensible Computational Chemistry Environment Basis Set Database, Version 10/29/02, as developed and distributed by the Molecular Science Computing Facility, EMSL which is part of the PNL.
GAMESS-PC As with GAMESS-US but specifically for PC running Pentium chips.  Runs under any version of windows except maybe 3.1 and available at no cost.  There is a DOS version but it is not free.
Gamess-us GAMESS is a program for ab initio quantum chemistry.  Versions are available for Unix, Linux and PC O/S.
Gaussian98 Gaussian is a program for ab initio type calculations.
Ghemical Ghemical is a viewer program with capabilities  which may be of particular interest to the users of the quantum chemistry program GAMESS.  Ghemical can extract the geometry from GAMESS output files, but cannot yet display plots of MOs, density, or vibrational modes.  Versions are available for Windows, MAC and Linux  
MOPAC WinMopac7.21 is a powerful tool for semi empirical calculations of chemical molecules. This program has unified old DOS version MOPAC7 with some improvements which we have made and a convenient windows interface, and an integrated external molecular viewer(RasWin). The Windows interface includes all editing functions, a setting menu and some other features.
OpenDX If you need visualization for anything from examining simple data sets to analyzing complex, time-dependent data from disparate sources, OpenDX has what you need: features and functions that let you easily gain meaningful insight into your data.
OPEP OPEP (Optimal Partitioning of Electric Properties) is a suite of Fortran programs, featuring a Tcl/Tk graphical user interface to facilitate the fit of electric charges and multipoles, as well as models of distributed polarizabilities.
ORAC ORCA is a flexible, reasonably efficient and easy-to-use general purpose tool for quantum chemistry with specific emphasis on spectroscopic properties of open-shell molecules. It features a wide variety of standard quantum chemical methods ranging from semiempirical methods to DFT to correlated ab initio methods.
POLYRATE A program (designed by Prof. Joel Bowman and others) to
calculate vibrational frequencies and more by going beyond the harmonic oscillator approximation.  (Add the HPFREQ option to the FREQ command.)
SWizard SWizard is a program that runs under MS Windows NT/2000/XP) for postprocessing spectral data. A spectrum is calculated as a sum of Gaussian or/and Lorentzian bands or the mixture of these functions.  For UV-vis spectra, the program reads excitation energies and oscillator strengths directly from an output file and produces an electronic spectrum of a molecule as an ASCII text file.  Though there is a fee, it is minimal
TURBOMOLE TurboMole is a qm program that runs on Unix/Linux machines.  It uses semi-direct algorithms with adjustable main memory and disk space requirements.  There is full use of all point groups, efficient integral evaluation, stable and accurate grids for numerical, integration, low memory and disk space requirements, and implementation of the very efficient RI technique (DFT, SCF, MP2, CC2).
VASP VAMP/VASP is a package for performing ab-initio quantum-mechanical molecular dynamics (MD) using pseudopotentials and a plane wave basis set.  VAMP/VASP is not public domain but the site doesn't say what it costs.