Common Terms and Acronyms

Following are brief definitions of a number of terms that are commonly enocountered  

Antibonding Molecular Orbital. A Molecular Orbital that is andbonding between particular atomic centers. The opposite is a Bonding Molecular Orbital. 

Atomic Orbital. A function centered on an atom. Atomic orbitals typically closely resemble the solutions to the hydrogen atom (s, p, d.type orbitals). 

Boltzmann Equation. The equation which relates the composition of equilibrium mixtures to relative thermochemical stabilities and temperature. 

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Molecular modeling, like all other technical disciplines, has its own jargon. Much of this is described in Appendix B (Common Terms and Acronyms), and only one aspect will be addressed here. This concerns specification of theoretical model used for property calculation together with theoretical model used for equilibrium (or transition-state) geometry calculation. 

In addition to Appendix A providing Supplementary Data in support of several chapters in Section II, Appendix B provides a glossary of Common Terms and Acronyms associated with molecular mechanics and quantum chemical models. 

The intention of this section is to provide to the reader a rapid and comprehensive reference for the most common definitions and acronyms used in mass spectrometry. Currently lUPAC has initiated a project to update and extend the definitions of terms related to the field of mass spectrometry. The definitions presented here (Table 1.6) are from the third draft document [16]. For more details and the latest updates, please consult www.msterms.com. 

Here we list a number of mathematical symbols, specialist terms, and acronyms used throughout this text. Where possible we have used the commonly accepted convention, although some duplication and repetition is present as symbols and acronyms are not always used consistendy in the literature. In places we have indeed used different symbols to identify the same parameters. Generally, this is in order to maintain consistency with the nomenclature found in the original work that we describe or review. 

Chromatography— like other sciences— uses special terminology and acronyms. Navigating through these may occasionally become frustrating for the nonspecialist reader. As a guide, commonly used terms and acronyms in chromatography are summarized in Table 2. 

In addition to capitalization, move 1 of the Methods section is also an excellent place to examine how chemists use abbreviations and acronyms in their writing. Abbreviations are short forms of words or phrases where each letter is often pronounced (e.g., DNA) acronyms are short forms of words or phrases that form pronounceable words (e.g., NASA). Both are common in chemical writing, in part because they make the writing more concise. A few abbreviations are so common that they can be used without ever introducing the full term (e.g., DNA, IR, NMR, UV, RNA). Most abbreviations, however, need to be dehned before they can be used on their own in such cases, abbreviations are placed in parentheses immediately/oHowing the full terms that they represent. For example. 

Master the basic facts and terms. Few can make sense of the material on prescription drugs without having some familiarity with common terms, names, and acronyms. Try to learn the basic terminology careful and precise usage lends authority to research. 

A large number of terms, symbols, and equations were given in this chapter. The equations are gathered together in Table 3, along with a few others that will be introduced in later chapters. As commonly used, some symbols are slightly different for GC and LC, but this should not diminish the value of the table. The Appendix contains a list of symbols and acronyms used in this text. 

Despite the obvious limitation of the LCAO procedure as revealed by the Hj and H2 problems it still is the most popular scheme used in the theoretical study of polyatomic molecules. There is a bewildering number of approximate methods, commonly distinguished in terms of cryptic acronyms, designated as either ab initio or semi-empirical, but all of them based on the LCAO construction of molecular orbitals. The precise details can be found in many books and reviews. The present summary uses the discussion of Richards and Cooper [92] as a guide. 

The following acronyms for organizations, drugs, and other terms are commonly encountered in discussions of drug abuse. 

Electrochemical Detectors. The only electrochemical detector in current use is amperometric. However, some workers have used the term cou-lometric for detectors that operate at a high current efficiency and others have used the term polarographic when the electrode is mercury. The acronym LCEC is in common use to represent LC with electrochemical detection. 

PUVA is the acronym originally introduced to describe the combined administration of psoralen and subsequent exposure to high-intensity ultraviolet radiation from an artificial source (UVA). In the United States, orally administered 8-methoxypsor-alen (8-MOP) is the psoralen most frequently used in combination with UVA light therapy and will be the focus of this discussion. However, the term PUVA also refers to therapy with other oral and topical psoralens, most commonly 4,5, 8-trimethylpsoralen (TMP), a synthetic psoralen, and 5-methoxypsoralen (5-MOP), not available in the United States. 

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