Gerli

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... 

Caution Geometry optimi/ation s of large molecules may take Ion ger Ih an you expect. Th e n um her of com pii tin g cycles req iiired for a con jugate gradien t calculation is approximately proportional... 

Note MM-i- is derived from the public domain code developed by Dr. Norm an Allinger, referred to as M.M2( 1977), and distributed by the Quantum Chemistry Program Exchange (QCPE). The code for MM-t is not derived from Dr. Allin ger s present version of code, which IS trademarked MM2 . Specifically. QCMPOlO was used as a starting point Ibr HyperChem MM-t code. The code was extensively modified and extended over several years to include molecular dynamics, switching functuins for cubic stretch terms, periodic boundary conditions, superimposed restraints, a default (additional) parameter scheme, and so on. 

The Extended Iliickel method also allows the inclusion ofd orbitals for third row elements (specifically, Si. P, Sand CD in the basis set. Since there arc more atomic orbitals, choosing this option resn Its in a Ion ger calc ii 1 at ion. Th e m ajor reason to in cin de d orbitals is to improve the description of the molecular system. 

HyperChem s MM-i- force field uses the latest MM2 (1991) parameters and atom types (provided directly by Dr. Alliugei) with the 1977 functional form X. H.. Allinger, 7 Am. Chern. Soc., 99, 8127 (1977),. 1,.. Allin ger and Y. H. Yuh, Qiiari tnm Ch cm istry Program... 

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

HypcrCti cm models tli c vibration s of a rn o Iconic as a set of N poiri t masses (the nuclei of the atoms ) with each vibrating about itsetjui-libriurn (optirn ized) position, flic etitiilibrium position s arc dctcr-mined by solving the eleotronic -Sobiodin ger etju ation. ... 

Ger. Weisse Masse, white mass later Wisuth and Bisemutum) In early times bismuth was confused with tin and lead. Claude Geoffroy the Younger showed it to be distinct from lead in 1753. 

Cooper, S. R. 1992, Crown Compounds. Toward Future Applications, VCH Verlag Weinheim, Ger. 

Ehrfaart, G. Rusefaig H. 1972, Arzneimittel Entwicklimg, fVirkung, Darstellung, 2nd Verlag Chemie Weinheim, Ger. 

Fieser, L. F. Fieser, M. 1959, Steroids, p. 507, Reinhold New York Chapman Hall London Fieser, L. F. Fieser, M. 1959, Steroide, Verlag Chemie Weinheim, Ger. 

Helimann, H. Opitz, G. I960, x-Aminoalkylianng, Verlag Chemie Weinheiffi, Ger. 

MolTmann, R. W. 1967, Dehydrobenzene and Cycloalkynes, Verlag Chemie Weinheim, Ger. and Academic Press New York London... 

Weissermel, K- Arpe, H.-J. 1978, Industrielle organische Chemie, 2nd edn., Verlag Chemie Weinheim, Ger. 

Ludwig Claisen was a Ger man chemist who worked during the last two decades of the nineteenth century and the first two decades of the twentieth His name is associated with three reac tions The Claisen-Schmidt reaction was presented in Section 18 10 the Claisen condensation is discussed in this section and the C/a/sen rearrangement will be intro duced in Section 24 13... 

The product of this reaction as its sodium salt is called a Meisenheimer complex after the Ger man chemist Jacob Meisenheimer who reported on their formation and reactions in 1902 A Meisenheimer complex corresponds to the product of the nucleophilic addition stage in the addition-elimination mechanism for nucleophilic aromatic substitution... 

The higher terpenes are formed not by successive addition of C5 units but by the coupling of simpler terpenes Thus the triterpenes (C30) are derived from two mole cules of farnesyl pyrophosphate and the tetraterpenes (C40) from two molecules of ger anylgeranyl pyrophosphate These carbon-carbon bond forming processes involve tail to tail couplings and proceed by a more complicated mechanism than that just described... 

Berkert, U. Allin ger, N.L. Molecular Mechanics, American Chemical Society Monograph 177, Washington, D.C., 1982. 

Although UHF is often a better theoretical treatment of open-shell system s th an th e RHF (h alf-electron) m eth ods, it takes Ion ger to compute. Separate matrices for electrons of each spin roughly double the length of the calculation. 

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