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. The importance of this subject stems from the fact that, with the exception of some relatively recent findings related to the hydrogen molecular ion, achieving an accurate quantum mechanical depiction of chemical systems analytically, or in a closed form, is not feasible. The complexity inherent in many-body problem exacerbates the challenge of providing detailed descriptions in quantum mechanical systems. While computational results normally complement the information obtained by chemical experiments, it can in some cases predict unobserved chemical phenomena.
Theoretical chemistry is the branch of chemistry which develops theoretical generalizations that are part of the theoretical arsenal of modern chemistry: for example, the concepts of chemical bonding, chemical reaction, valence, the surface of potential energy, molecular orbitals, orbital interactions, and molecule activation.
In chemistry, an acid dissociation constant is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction
Chemometrics is the science of extracting information from chemical systems by data-driven means. Chemometrics is inherently interdisciplinary, using methods frequently employed in core data-analytic disciplines such as multivariate statistics, applied mathematics, and computer science, in order to address problems in chemistry, biochemistry, medicine, biology and chemical engineering. In this way, it mirrors other interdisciplinary fields, such as psychometrics and econometrics.
A chemical database is a database specifically designed to store chemical information. This information is about chemical and crystal structures, spectra, reactions and syntheses, and thermophysical data.
Cheminformatics refers to the use of physical chemistry theory with computer and information science techniques—so called "in silico" techniques—in application to a range of descriptive and prescriptive problems in the field of chemistry, including in its applications to biology and related molecular fields. Such in silico techniques are used, for example, by pharmaceutical companies and in academic settings to aid and inform the process of drug discovery, for instance in the design of well-defined combinatorial libraries of synthetic compounds, or to assist in structure-based drug design. The methods can also be used in chemical and allied industries, and such fields as environmental science and pharmacology, where chemical processes are involved or studied.
Drug design, often referred to as rational drug design or simply rational design, is the inventive process of finding new medications based on the knowledge of a biological target. The drug is most commonly an organic small molecule that activates or inhibits the function of a biomolecule such as a protein, which in turn results in a therapeutic benefit to the patient. In the most basic sense, drug design involves the design of molecules that are complementary in shape and charge to the biomolecular target with which they interact and therefore will bind to it. Drug design frequently but not necessarily relies on computer modeling techniques. This type of modeling is sometimes referred to as computer-aided drug design. Finally, drug design that relies on the knowledge of the three-dimensional structure of the biomolecular target is known as structure-based drug design. In addition to small molecules, biopharmaceuticals including peptides and especially therapeutic antibodies are an increasingly important class of drugs and computational methods for improving the affinity, selectivity, and stability of these protein-based therapeutics have also been developed.
In the physical sciences, a partition coefficient (P) or distribution coefficient (D) is the ratio of concentrations of a compound in a mixture of two immiscible solvents at equilibrium. This ratio is therefore a comparison of the solubilities of the solute in these two liquids. The partition coefficient generally refers to the concentration ratio of un-ionized species of compound, whereas the distribution coefficient refers to the concentration ratio of all species of the compound.
Quantitative structure–activity relationship models are regression or classification models used in the chemical and biological sciences and engineering. Like other regression models, QSAR regression models relate a set of "predictor" variables (X) to the potency of the response variable (Y), while classification QSAR models relate the predictor variables to a categorical value of the response variable.
Lipinski's rule of five, also known as Pfizer's rule of five or simply the rule of five (RO5), is a rule of thumb to evaluate druglikeness or determine if a chemical compound with a certain pharmacological or biological activity has chemical properties and physical properties that would likely make it an orally active drug in humans. The rule was formulated by Christopher A. Lipinski in 1997, based on the observation that most orally administered drugs are relatively small and moderately lipophilic molecules.
Carlos Simmerling is a full professor of chemistry at the State University of New York at Stony Brook. He is associate director of the Louis and Beatrice Laufer Center for Physical and Quantitative Biology. Simmerling received his Bachelor of Arts in 1991 from the University of Illinois at Chicago and then his doctorate in 1994 from the same institution. His postdoctoral work was performed at the University of California, San Francisco under the direction of Peter Kollman. His primary field of interest is computational structural biology with a focus on methods of conformational sampling and protein structure prediction. He is a member of the AMBER development team.
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.
MDL Information Systems, Inc. was a provider of R&D informatics products for the life sciences and chemicals industries. The company was launched as a computer-aided drug design firm in January 1978 in Hayward, California. The company was acquired by Symyx Technologies, Inc. in 2007. Subsequently Accelrys merged with Symyx. The Accelrys name was retained for the combined company. In 2014 Accelrys was acquired by Dassault Systemes. The Accelrys business unit was renamed BIOVIA.
ChemSpider is a freely accessible online database of chemicals owned by the Royal Society of Chemistry. It contains information on more than 100 million molecules from over 270 data sources, each of them receiving a unique identifier called ChemSpider Identifier.
Chemaxon is a cheminformatics and bioinformatics software development company, headquartered in Budapest with 250 employees. The company also has offices in Cambridge, San Diego, Basel and in Prague. and it has distributors in China, India, Japan, South Korea, Singapore, and Australia.
Druglikeness is a qualitative concept used in drug design for how "druglike" a substance is with respect to factors like bioavailability. It is estimated from the molecular structure before the substance is even synthesized and tested. A druglike molecule has properties such as:
A nuclear magnetic resonance spectra database is an electronic repository of information concerning Nuclear magnetic resonance (NMR) spectra. Such repositories can be downloaded as self-contained data sets or used online. The form in which the data is stored varies, ranging from line lists that can be graphically displayed to raw free induction decay (FID) data. Data is usually annotated in a way that correlates the spectral data with the related molecular structure.
Antony John Williams is a British chemist and expert in the fields of both nuclear magnetic resonance (NMR) spectroscopy and cheminformatics at the United States Environmental Protection Agency. He is the founder of the ChemSpider website that was purchased by the Royal Society of Chemistry in May 2009. He is a science blogger and an author.
Chemicalize is an online platform for chemical calculations, search, and text processing. It is developed and owned by ChemAxon and offers various cheminformatics tools in freemium model: chemical property predictions, structure-based and text-based search, chemical text processing, and checking compounds with respect to national regulations of different countries.
The n-octanol-water partition coefficient,Kow is a partition coefficient for the two-phase system consisting of n-octanol and water. Kow is also frequently referred to by the symbol P, especially in the English literature. It is also called n-octanol-water partition ratio.
