Fityk is nonlinear curve-fitting and data analysis software. It allows data visualization, separation of overlapping peaks, and least squares fitting using standard Levenberg-Marquardt algorithm, a genetic algorithm, or Nelder-Mead simplex method. It knows about many functions (mostly bell-shaped, like Gaussian, Loretzian, Pearson 7, Voigt, Pseudo-Voigt, and Doniach-Sunjic) and user-defined functions can be easily added. It also enables background subtracting, data calibration, and task automation with a simple script language. It is mainly used to analyze powder diffraction patterns, chromatography, photoluminescence, infrared, and Raman spectroscopy, but it can be used to fit analytical functions to any kind of data.
The Gnome Chemistry Utils includes the following programs: a 2D chemical editor (GChemPaint), a chemical calculator (computes raw formule, molar weight, mass composition, and isotopic pattern), a 3D molecule viewer using OpenGL to display molecular models, a crystal structure viewer and editor, a spectrum viewer, and a periodic table of the elements.
GAMGI (General Atomistic Modelling Graphic Interface) is a program to build, view, and analyze atomic strucures such as molecules, crystals, glasses, liquids, etc. It aims to be useful for: the scientific community working in Atomistic Modelling that needs a graphic interface to build input data and to view and analyse output data, calculated with Ab-Initio and Molecular Mechanics programs; the scientific community at large studying chemistry, physics, materials science, geology, etc., that needs a graphic interface to view and analyse atomic structural information and to prepare images for presentations in classes and seminars; teaching chemistry and physics in secondary schools and universities; science promotion in schools, exhibitions and science museums.
GROMACS is a versatile package to perform molecular dynamics, i.e. simulate the Newtonian equations of motion for systems with hundreds to millions of particles. It is primarily designed for biochemical molecules like proteins and lipids that have a lot of complicated bonded interactions, but since GROMACS is extremely fast at calculating the nonbonded interactions (that usually dominate simulations) many groups are also using it for research on non-biological systems, e.g. polymers.
lazar (Lazy-Structure-Activity Relationships) is a tool for the prediction of toxic activities of chemical structures. lazar derives predictions from databases with experimental toxicity data. It searches in these databases for compounds with similar structures and calculates the prediction from their measured activities.
The FOX (Free Objects for Crystallography) program is made for determining crystal structure ab initio from diffraction data (mostly powder diffraction). It is built on an object-oriented crystallographic computing library called ObjCryst++. FOX features a graphical interface, including a 3D OpenGL display of the crystal structure. It provides a versatile description of the crystal structures (such as atoms, molecules, and polyhedra). Special positions and overlapping atoms are automatically handled without any a priori knowledge.
APBS is a software package for the numerical solution of the Poisson-Boltzmann equation (PBE), one of the most popular continuum models for describing electrostatic interactions between molecular solutes in salty, aqueous media. Continuum electrostatics plays an important role in several areas of biomolecular simulation, including simulation of diffusional processes to determine ligand-protein and protein-protein binding kinetics, implicit solvent molecular dynamics of biomolecules, solvation and binding energy calculations to determine ligand-protein and protein-protein equilibrium binding constants and aid in rational drug design, and biomolecular titration studies.
PDB2PQR is a Python software package that automates many of the common tasks of preparing structures for continuum electrostatics calculations, providing a platform-independent utility for converting protein files in PDB format to PQR format. These tasks include adding a limited number of missing heavy atoms to biomolecular structures, determining side-chain pKas, placing missing hydrogens, optimizing the protein for favorable hydrogen bonding, assigning charge and radius parameters from a variety of force fields.