The Neglect-of-Differential-Overlap Methods of Molecular Orbital Theory

Principles of Nucleic Acid Structure

“…field methods in the CNDO/2 (Complete Neglect of Differential Overlap) approximation (66). Other schemes to evaluate '"IT and (T charges individually are those developed by Hiickel (67) and by Del Re (68,69).…”

“…Treatment of such deviations from "ideal" geometry is possible with the consistent force field method (CFF) (64,74), which produces a more realistic picture of the molecular flexibility. At yet a higher level of sophistication, quantum chemical calculations, mostly of the form described by the extended Huckel method (75,76), by CNDO/2 (66) or PCILO (Perturbative Configuration Interactions using Localized Orbitals) (77,78), as well as "ab initio" methods (79), are applied. These are, however, restricted to small molecules like mononucleotides and yield, besides torsional potentials, information on charge distribution, electrostatic and ionization potentials, and dipole moments.…”

Tight-Binding Configuration Interaction (TBCI): A Noniterative Approach to Incorporating Electrostatics into Tight Binding

“…The elements of c are the orbital coefficients in eq . On the basis of previous work, ,, we will assume zero differential overlap (ZDO) , so that the density matrix of CSF j in the atomic orbital representation becomes The ZDO approximation is the reason that the atomic-orbital overlap matrix is neglected in eq . In a previous work on TB, it was found that neglecting the overlap gave a more balanced set of approximations …”

Modified all‐valence INDO/spd method for ground and excited state properties of isolated molecules and molecular complexes

“…5-40, see also reviews [41][42][43][44][45][46][47]. Some of them (especially for sp-electron-containing elements) presently are very popular and widely applied to solve many chemical or physicochemical problems, e.g., CNDO/S [8], INDO/S 191, MINDO/~ [lo], MNDO [ 113. These methods give really a good description of some properties of isolated molecules but contain a number of totally adjustable parameters.…”