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Intermediate Neglect of Differential Overlap Approximation INDO

Various theoretical methods (self-consistent field molecular orbital (SCF-MO) modified neglect of diatomic overlap (MNDO), complete neglect of differential overlap (CNDO/2), intermediate neglect of differential overlap/screened approximation (INDO/S), and STO-3G ab initio) have been used to calculate the electron distribution, structural parameters, dipole moments, ionization potentials, and data relating to ultraviolet (UV), nuclear magnetic resonance (NMR), nuclear quadrupole resonance (NQR), photoelectron (PE), and microwave spectra of 1,3,4-oxadiazole and its derivatives <1984CHEC(6)427, 1996CHEC-II(4)268>. [Pg.398]

The widespread application of MO theory to systems containing a bonds was sparked in large part by the development of extended Hiickel (EH) theory by Hoffmann (I) in 1963. At that time, 7r MO theory was practiced widely by chemists, but only a few treatments of a bonding had been undertaken. Hoffmann s theory changed this because of its conceptual simplicity and ease of applicability to almost any system. It has been criticized on various theoretical grounds but remains in widespread use today. A second approximate MO theory with which we are concerned was developed by Pople and co-workers (2) in 1965 who simplified the exact Hartree-Fock equations for a molecule. It has a variety of names, such as complete neglect of differential overlap (CNDO) or intermediate neglect of differential overlap (INDO). This theory is also widely used today. [Pg.2]

The Intermediate Neglect of Differential Overlap (INDO) method, originally developed by Pople and Beveridge [8] and Pople et al. [44], uses the ZDO approximation [Eq. (26)] only for two-center integrals. The elements of the INDO Fock operator are therefore modified with respect to CNDO mainly by the inclusion of one-center exchange-type integrals (pv pv). [Pg.39]

Like their related methods such as the Intermediate Neglect of Differential Overlap (INDO) [2] and Modified Intermediate Neglect of Differential Overlap (MINDO) [6] the methods already mentioned have a number of features in common. They are all self-consistent field (SCF) methods that take into account electrostatic repulsion and exchange stabilization and where all integrals are evaluated by approximate means. They are further characterized by the fact that they all use a restricted basis set, that is, one s oibital and three p orbitals per atom, except for the hydrogen atom, which is represented by an s orbital. [Pg.110]

The interatomic exchange integrals would be zero in any approximation where diatomic differential overlap is neglected, while the intra-atomic exchange is included in the approximation called Intermediate Neglect of Differential Overlap (INDO). The form of hamiltonian in Eq. (10.72) is more restricted than the one which applies for the NDDO approximation. These restrictions are imposed by Eq. (10.34) as soon as the dipole moment operator cannot be expressed in terms of the Na s only. [Pg.172]

INDO/S Intermediate neglect of differential overlap/screened approximation. [Pg.116]

In the 1960s, several semiempirical SCF methods were proposed by Pople and co-workers the complete neglect of differential overlap (CNDO) method, the intermediate neglect of differential overlap (INDO) method, and the neglect of differential diatomic overlap (NDDO) approximation " " (Table 1). In 1968, Bene and Jaffe parametrized the CNDO method to study electronic spectra (CNDO/S). Ridley and Zerner developed the INDO method to predict electronic spectra (INDO/S). " In 1977, an alternative semiempirical approach with configuration interaction (Cl), local neglect of differential overlap for spectroscopy (LNDO/S), was proposed. " ... [Pg.468]

Various NDO schemes differ from CNDO in that they do not utilize fully the ZDO approximation. These schemes are discussed in the book by Pople and Beveridge (1970). In the intermediate neglect of differential overlap (INDO) model the differential overlaps between orbitals on the same atom are kept in one-center two-electron integrals, while the neglect of diatomic differential overlap (NDDO) model neglects only diatomic differential overlaps in any two-electron integral. [Pg.82]

Further approximations of the Hiickel method were removed with the introduction of the complete neglect of differential overlap (CNDO) method, which is a slightly more sophisticated method for dealing with the terms H,k that appear in the secular equations for the coefficients. The introduction of CNDO opened the door to an avalanche of similar but improved methods and their accompanying acronyms, such as intermediate neglect of differential overlap (INDO), modified neglect of differential overlap (MNDO), and the Austin Model 1 (AMI, version 2 of MINDO). Software for all these procedures is now readily available, and reasonably sophisticated calculations can be run even on handheld computers. [Pg.399]

Highest occupied molecular orbital Intermediate neglect of differential overlap Linear combination of atomic orbitals Local density approximation Local spin density functional theory Lowest unoccupied molecular orbital Many-body perturbation theory Modified INDO version 3 Modified neglect of diatomic overlap Molecular orbital Moller-Plesset... [Pg.124]

Intermediate Neglect of Differential Overlap Approximation (INDO)... [Pg.83]


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See also in sourсe #XX -- [ Pg.107 , Pg.117 , Pg.118 ]




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INDO (intermediate neglect of differential

Intermediate Neglect of Differential Overlap

Intermediate Neglect of Differential Overlap INDO)

Intermediate neglect of differential

Intermediate neglect of differential overlap approximation

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Neglect of Differential Overlap

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