Computational Chemistry

This energy, which includes internuclear repulsion, sinceEtotalHF includes this (Eq.5.93), is the MP2 energy normally printed ou ...

can of course be augmented (Section 5.3.3) with diffuse functions, and the 6–31G* with H polarization functions (6–31G). MP2 cal ...

single-point and optimized energies of butanone are#231.68593 and#231.68818 h, a difference of 0.00225 h (2.3 mh) or 6 kJ mol#^1 ...

not be a stationary point) on another. Thus fluoro- and difluorodiazomethane are HF minima but are MP2/6–31G transition states [ ...

CH 3 NC to CH 3 CN Transition state 0 K relative E¼ 173 Product 0 K relative E¼# 120 Ea¼DH{þRT¼DH{þ2.48¼174.0 O 107.2 107.2, sic ...

DH{¼171.5 DGreact¼#119.3 DG{¼169.2 DHreact¼#120.0 Cyclopropylidene to allene Transition state 0 K relative E¼25.7 Product 0 K re ...

HF theory (Sections 5.2.3.1–5.2.3.6) starts with a total wavefunction or molecu- lar wavefunctioncwhich is a Slater determinant ...

Diwas obtained fromD 1 by promoting an electron from spin orbitalc 2 ato the spin orbitalc 3 a. Another possibility is Dj¼ 1 ffi ...

C 1 ¼c 11 D 1 þc 21 D 2 þc 31 D 3 þ(((þci 1 Di C 2 ¼c 12 D 1 þc 22 D 2 þc 32 D 3 þ(((þci 2 Di ... Ci¼c 1 iD 1 þc 2 iD 2 þc 3 iD ...

computational tours de force are, although of limited direct application, important for evaluating the efficacy, by comparison, ...

LCAO expansion, Eq.5.164¼5.52. A widely-used version of the MCSCF method is the CASSCF method, in which one carefully chooses th ...

doubles (CCSD) orcoupled cluster singles, doubles and triples (CCSDT) method: T^CCD¼eT^^2 CHF T^CCSD¼eðT^^1 þT^^2 ÞCHF T^CCSDT¼e ...

connection with Figs.5.20and5.21). There is some limited evidence thatwhen a correlation method is already being used, one tends ...

physical behaviour would seem to have a conceptual flaw, and in fact lack of size- consistency also places limits on the utility ...

H–H bond energy of 435 kJ mol#^1 ) above the accepted exact energy of#1.17439 h (Fig.5.18). Variational behavior is helpful beca ...

this we are assuming that if there were no interactions at all between A and B at the geometry of the AB species, then the AB en ...

room-temperature, 298 K, of the dimer minus twice the enthalpy of the monomer. Here are some calculated values of this binding e ...

5.5 Applications of the Ab initio Method................................... An extremely useful book by Hehre [ 39 ] discusses c ...

somewhat different than in the gas phase to which ab initio reactions usually apply (although structures and energies can be cal ...

Clearly, the X-ray-inferred H–X distance will be less than the actual internuclear distance measured by electron diffraction, ne ...