chemistry

Quantum Chemistry Program Exchange

Quantum Chemistry Program Exchange is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Quantum Chemistry Program Exchange rather than just read about it. In short: The Quantum Chemistry Program Exchange (QCPE) was an organization located at Indiana University Bloomington from 1963 to 2007. It was devoted to the distribution of computational chemistry software before electronic file transfer on the internet became a widely available method of software distribution.

Key takeaways

Quantum Chemistry Program Exchange belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Quantum Chemistry Program Exchange to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Quantum Chemistry Program Exchange from memory before moving on to harder problems.

Reference excerpt

The Quantum Chemistry Program Exchange (QCPE) was an organization located at Indiana University Bloomington from 1963 to 2007. It was devoted to the distribution of computational chemistry software before electronic file transfer on the internet became a widely available method of software distribution. The QCPE was 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 until 1969. Funding continued under an interim grant from the National Science Foundation 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 and magnetic tape drives delivered by mail, before adopting floppy disks and CD-ROMs, and eventually electronic delivery by FTP. 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 1980s and early 1990s, the QCPE also organized annual summer workshops to train scientists in the use of its more popular software. At its peak in the mid-1980s, the QCPE had over 2000 members, over 400 programs available, and an annual income of nearly $400,000. The most visible legacy of the QCPE is the thousands of software citations to the QCPE Bulletin in scientific publications over four 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 (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 (QCPE #455, #688, #689). Other popular software distributed by the QCPE included POLYATOM (QCPE #47, #199), CNDO/2 (QCPE #91), AMPAC (QCPE #506), CRYSTAL (QCPE #577), Molden (QCPE #619), and MM2 / MM3 (QCPE #690-#698).

References

Worked examples

Example 1 — a first encounter with Quantum Chemistry Program Exchange

Start with the simplest possible case. Write down what Quantum Chemistry Program Exchange claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Quantum Chemistry Program Exchange before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Quantum Chemistry Program Exchange ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Quantum Chemistry Program Exchange

In research: Quantum Chemistry Program Exchange appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Quantum Chemistry Program Exchange in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Quantum Chemistry Program Exchange is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1963 establishments in Indiana, 2007 disestablishments in Indiana, American organizations established in 1963, so understanding it makes those chapters shorter.
In everyday life: Look for Quantum Chemistry Program Exchange outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Quantum Chemistry Program Exchange in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Quantum Chemistry Program Exchange means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Quantum Chemistry Program Exchange out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Quantum Chemistry Program Exchange in simple terms?

Why does Quantum Chemistry Program Exchange matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Quantum Chemistry Program Exchange?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Quantum Chemistry Program Exchange.