The Quantum Chemistry Program Exchange (QCPE) was an organization located at

Indiana University Bloomington Indiana University Bloomington (IU Bloomington, Indiana University, IU, IUB, or Indiana) is a public university, public research university in Bloomington, Indiana, United States. It is the flagship university, flagship campus of Indiana Univer ...

from 1963 to 2007 that was devoted to the distribution of

computational chemistry Computational chemistry is a branch of chemistry that uses computer simulations to assist in solving chemical problems. It uses methods of theoretical chemistry incorporated into computer programs to calculate the structures and properties of mol ...

software before electronic file transfer on the internet became a widely available method of software distribution. The QCPE was originally founded by Prof. Harrison Shull and was managed by Richard Counts for most of its existence. Financial support for the QCPE was originally provided by the

Air Force Office of Scientific Research The Air Force Research Laboratory (AFRL) is a scientific research and development detachment of the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of direct-energy based aerospace warf ...

until 1969, and funding continued under an interim grant from the

National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...

in 1971 until it became financially self-sustaining in 1973. The QCPE maintained a catalog of software that expanded through regular contributions from chemistry software developers. New software contributions were announced through a quarterly QCPE Newsletter that were eventually formalized into a QCPE Bulletin in 1981, which allowed for software citations to numbered software entries in the Bulletin that announced their release. QCPE members paid for subscriptions to the Newsletter/Bulletin and additionally paid a processing and delivery fee to receive software from the QCPE catalog. The software distribution options expanded alongside technological development, starting from

punched cards A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were wide ...

and magnetic tape drives delivered by

mail The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...

, before adopting

floppy disks A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...

and

CD-ROMs A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data computers can read, but not write or erase. Some CDs, called enhanced CDs, hold both computer data and a ...

, and eventually electronic delivery by

FTP The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and dat ...

. The QCPE grew rapidly in its early days, with about 400 members and a catalog of nearly 100 programs after its first 3 years of operation. In the 1980's and early 1990's, the QCPE also organized annual summer workshops to train scientists in the use of its more popular software. At its peak in the mid-1980's, the QCPE had over 2000 members, over 400 programs available, and an annual income near $400,000. The most visible legacy of the QCPE are the thousands of software citations to the QCPE Bulletin in scientific publications over 4 decades, with a peak of over 1000 per year in the early 1990's. The most popular software in the early days of the QCPE was

GAUSSIAN Carl Friedrich Gauss (1777–1855) is the eponym of all of the topics listed below. There are over 100 topics all named after this German mathematician and scientist, all in the fields of mathematics, physics, and astronomy. The English eponymo ...

(QCPE #236, #368, #406) before it was removed from the QCPE catalog to become commercial software, and the most popular software in its later years was

MOPAC MOPAC is a computational chemistry software package that implements a variety of semi-empirical quantum chemistry methods based on the neglect of diatomic differential overlap (NDDO) approximation and fit primarily for gas-phase thermochemistry ...

(QCPE #455, #688, #689). Other popular software distributed by the QCPE included POLYATOM (QCPE #47, #199),

CNDO/2 Complete Neglect of Differential Overlap (CNDO) is one of the first semi empirical methods in quantum chemistry. It uses the ''frozen core approximation'', in which only the outer valence electrons are explicitly included, and the approximation of ...

(QCPE #91),

AMPAC AMPAC is a general-purpose semiempirical quantum chemistry program. It is marketed by Semichem, Inc. and was developed originally by Michael Dewar and his group. The first version of AMPAC (2.1) was made available in 1985 through the Quantum Che ...

(QCPE #506),

CRYSTAL A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

(QCPE #577),

Molden Molden is a general molecular and electronic structure processing program. Major features * Reads output from the ab initio packages GAMESS (US), Gaussian, MOLPRO, PySCF and from semi-empirical packages such as MOPAC, and supports a num ...

(QCPE #619), and MM2 / MM3 (QCPE #690-#698).

References

{{reflist Software distribution Indiana University Bloomington Organizations established in 1963 Organizations disestablished in 2007 Computational chemistry software 1963 establishments in Indiana 2007 disestablishments in Indiana