SchS

These atomic orbitals, called Slater Type Orbitals (STOs), are a simplification of exact soil tion s of the Sch rbdin ger eq nation for the... 

Note You cannot use the Hxicndcd Hiickel method or any one of th e-SCH m eth ods with theCI option being turn ed on forgeometry optim i/.ation s, m olecular dynam ics sim ulation s or vibrational cal-culations, in the ctirrcrit version ofHypcrChem. 

Th c eigen value of ih is Sch riidiri gcr equation. the electron ie energy deperi ds parametrically, as sh own, on the coord in ales of th e nuclei (assumed to he fixed for the purposes of calcti lali ri g each Heie.lK), bin variable in general), I h e electronic energy, combined with y, (K,K) is the total energy of Single Point semi-em pirical calculation s. 

Molecular quan turn mcchan ics finds the solution to a Sch rddinger equation for an electronic Hamiltonian, H i, that gives a total energy, K(,. (.(R) + (R.R). Repeated solutions at different nuclear configurations, R, lead to some approximate potential energy sur-... 

An esliniaie of the hybridization state of an aioin in a molecule can be obtained from the group ol ihc periodic table that the atom resides in (which describes the number of valence elecironsi and the connectivity (coordination of the atom ). The IlyperChem default sch em e uses ih is estiin ate to assign a h ybridi/ation slate to all atom s from th e set (n ii 11, s, sp, sp, sp2-- and sp The special... 

Within the Born-Oppenhcimer approximation discussed earlier, yon can solve an electronic Sch rod In ger ec nation... 

HyperChcin s ah mitio calculations solve the Roothaan equations (.h9 i on page 225 without any further approximation apart from th e 11 se of a specific fin iie basis set. Th ere fore, ah initio calcii lation s are generally more accurate than semi-enipirical calculations. They certainly involve a more fundamental approach to solving the Sch riidiiiger ec nation than do semi-cmpineal methods. 

Usually, con traction s arc determ in cd from atom ic SCh calcula-tioris. In these calculations one uses a relatively large basis of uncontracted Gaussiaris, optim i/.es all exponents, and determines th e SCH coefficien is of each of the derived atom ic orbitals, fh c optim i,red e.spon en ts and SCH coefficien Ls cati th en be used to derive sii itable con traction expon cn is an d con traction coefficien is fora smaller basis set to be used in subsequent rn olecu lar ca leu la-lion s. 

Note 2. Propargyl bromide itself also reacts with ammonia and therefore the interval between the addition of this compound and its conversion with the enethiolate should be kept as short as possible. Inverse addition was applied if propargyl bromide is added to the enthiolate solution, the primary product partly isomerizes into H2C=C(5C2Hs)SCH=C=CH2 under the catalytic influence of the enethiolate. 

The observation of the variation of the SCH bands of thiazole with the nature and the position of the substituent has been interpreted as a proof of a fairly strong coupling between the various CH vibrators (203). The couplings are confirmed by the force-field calculation for thiazole that shows that the nature of the 1300-1000 band is rather complex. 

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