Computational chemistry is a branch of chemistry that uses computer simulation to assist in solving chemical problems. It uses methods of theoretical chemistry, incorporated into computer programs, to calculate the structures and properties of molecules, groups of molecules, and solids. It is essential because, apart from relatively recent results concerning the hydrogen molecular ion, the quantum many-body problem cannot be solved analytically, much less in closed form. While computational results normally complement the information obtained by chemical experiments, it can in some cases predict hitherto unobserved chemical phenomena. It is widely used in the design of new drugs and materials.
Nanoscale Molecular Dynamics is computer software for molecular dynamics simulation, written using the Charm++ parallel programming model. It is noted for its parallel efficiency and is often used to simulate large systems. It has been developed by the collaboration of the Theoretical and Computational Biophysics Group (TCB) and the Parallel Programming Laboratory (PPL) at the University of Illinois at Urbana–Champaign.
MOLPRO is a software package used for accurate ab initio quantum chemistry calculations. It is developed by Peter Knowles at Cardiff University and Hans-Joachim Werner at Universität Stuttgart in collaboration with other authors.
Gaussian is a general purpose computational chemistry software package initially released in 1970 by John Pople and his research group at Carnegie Mellon University as Gaussian 70. It has been continuously updated since then. The name originates from Pople's use of Gaussian orbitals to speed up molecular electronic structure calculations as opposed to using Slater-type orbitals, a choice made to improve performance on the limited computing capacities of then-current computer hardware for Hartree–Fock calculations. The current version of the program is Gaussian 16. Originally available through the Quantum Chemistry Program Exchange, it was later licensed out of Carnegie Mellon University, and since 1987 has been developed and licensed by Gaussian, Inc.
Dalton is an ab initio quantum chemistry computer program suite, consisting of the Dalton and LSDalton programs. The Dalton suite is capable of calculating various molecular properties using the Hartree–Fock, MP2, MCSCF and coupled cluster theories. Version 2.0 of DALTON added support for density functional theory calculations. There are many authors, including Trygve Helgaker, Poul Jørgensen and Kenneth Ruud.
Q-Chem is a general-purpose electronic structure package featuring a variety of established and new methods implemented using innovative algorithms that enable fast calculations of large systems on various computer architectures, from laptops and regular lab workstations to midsize clusters and HPCC, using density functional and wave-function based approaches. It offers an integrated graphical interface and input generator; a large selection of functionals and correlation methods, including methods for electronically excited states and open-shell systems; solvation models; and wave-function analysis tools. In addition to serving the computational chemistry community, Q-Chem also provides a versatile code development platform.
Psi is an ab initio computational chemistry package originally written by the research group of Henry F. Schaefer, III. Utilizing Psi, one can perform a calculation on a molecular system with various kinds of methods such as Hartree-Fock, Post-Hartree–Fock electron correlation methods, and density functional theory. The program can compute energies, optimize molecular geometries, and compute vibrational frequencies. The major part of the program is written in C++, while Python API is also available, which allows users to perform complex computations or automate tasks easily.
TURBOMOLE is an ab initio computational chemistry program that implements various quantum chemistry methods. It was initially developed by the group of Prof. Reinhart Ahlrichs at the University of Karlsruhe. In 2007, TURBOMOLE GmbH, founded by R. Ahlrichs, F. Furche, C. Hättig, W. Klopper, M. Sierka, and F. Weigend, took over the responsibility for the coordination of the scientific development of TURBOMOLE program, for which the company holds all copy and intellectual property rights. In 2018 David P. Tew joined the TURBOMOLE GmbH. Since 1987, this program is one of the useful tools as it involves in many fields of research including heterogeneous and homogeneous catalysis, organic and inorganic chemistry, spectroscopy as well as biochemistry. This can be illustrated by citation records of Ahlrich's 1989 publication which is more than 6700 times as of 18 July 2020. In the year 2014, the second Turbomole article has been published. The number of citations from both papers indicates that the Turbomole's user base is expanding.
Jaguar is a computer software package used for ab initio quantum chemistry calculations for both gas and solution phases. It is commercial software marketed by the company Schrödinger. The program was originated in research groups of Richard Friesner and William Goddard and was initially called PS-GVB.
The COLUMBUS PROGRAMS are a computational chemistry software suite for calculating ab initio molecular electronic structures, designed as a collection of individual programs communicating through files. The programs focus on extended multi-reference calculations of atomic and molecular ground and excited states. In addition to standard classes of reference wave functions such as CAS and RAS, calculations can be performed with selected configurations. Some features employ the atomic orbital integrals and gradient routines from the Dalton as well as MOLCAS program suites. COLUMBUS is distributed open-source under the LGPL license.
Spartan is a molecular modelling and computational chemistry application from Wavefunction. It contains code for molecular mechanics, semi-empirical methods, ab initio models, density functional models, post-Hartree–Fock models, and thermochemical recipes including G3(MP2) and T1. Quantum chemistry calculations in Spartan are powered by Q-Chem.
Semi-empirical quantum chemistry methods are based on the Hartree–Fock formalism, but make many approximations and obtain some parameters from empirical data. They are very important in computational chemistry for treating large molecules where the full Hartree–Fock method without the approximations is too expensive. The use of empirical parameters appears to allow some inclusion of electron correlation effects into the methods.
Car–Parrinello molecular dynamics or CPMD refers to either a method used in molecular dynamics or the computational chemistry software package used to implement this method.
CP2K is a freely available (GPL) quantum chemistry and solid state physics program package, written in Fortran 2008, to perform atomistic simulations of solid state, liquid, molecular, periodic, material, crystal, and biological systems. It provides a general framework for different methods: density functional theory (DFT) using a mixed Gaussian and plane waves approach (GPW) via LDA, GGA, MP2, or RPA levels of theory, classical pair and many-body potentials, semi-empirical and tight-binding Hamiltonians, as well as Quantum Mechanics/Molecular Mechanics (QM/MM) hybrid schemes relying on the Gaussian Expansion of the Electrostatic Potential (GEEP). The Gaussian and Augmented Plane Waves method (GAPW) as an extension of the GPW method allows for all-electron calculations. CP2K can do simulations of molecular dynamics, metadynamics, Monte Carlo, Ehrenfest dynamics, vibrational analysis, core level spectroscopy, energy minimization, and transition state optimization using NEB or dimer method.
Ascalaph Designer is a computer program for general purpose molecular modelling for molecular design and simulations. It provides a graphical environment for the common programs of quantum and classical molecular modelling ORCA, NWChem, Firefly, CP2K and MDynaMix . The molecular mechanics calculations cover model building, energy optimizations and molecular dynamics. Firefly covers a wide range of quantum chemistry methods. Ascalaph Designer is free and open-source software, released under the GNU General Public License, version 2 (GPLv2).
Frank Neese is a German theoretical chemist at the Max Planck Institute for Coal Research. He is the author of more than 440 scientific articles in journals of Chemistry, Biochemistry and Physics. His work focuses on the theory of magnetic spectroscopies and their experimental and theoretical application, local pair natural orbital correlation theories, spectroscopy oriented configuration interaction, electronic and geometric structure and reactivity of transition metal complexes and metalloenzymes. He is lead author of the ORCA quantum chemistry computer program. His methods have been applied to a range of problems in coordination chemistry, homogeneous catalysis, and bioinorganic chemistry.
A Pople diagram or Pople's Diagram is a diagram which describes the relationship between various calculation methods in computational chemistry. It was initially introduced in January 1965 by Sir John Pople,, during the Symposium of Atomic and Molecular Quantum Theory in Florida. The Pople Diagram can be either 2-dimensional or 3-dimensional, with the axes representing ab initio methods, basis sets and treatment of relativity. The diagram attempts to balance calculations by giving all aspects of a computation equal weight.
Teresa Lyn Head-Gordon is an American chemist and the Chancellor's Professor of Chemistry, Bioengineering, and Chemical and Biomolecular Engineering at the University of California, Berkeley. She is also a faculty scientist in the Chemical Sciences Division at the Lawrence Berkeley National Laboratory and a fellow of both the American Institute for Medical and Biological Engineering and the American Chemical Society (ACS).
Hans Lischka is an Austrian computational theoretical chemist specialized on development and application of multireference methods for the study of molecular excited states. He is the main developer of the software package Columbus for ab initio multireference calculations and co-developer of the Newton-X program.
