Intermediate Neglect of Differential Overlap INDO method

The intermediate neglect of differential overlap (INDO) method was at one time used for organic systems. Today, it has been superseded by more accurate methods. INDO is still sometimes used as an initial guess for ah initio calculations. 

The Intermediate Neglect of Differential Overlap (INDO) Method... 

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). 

The intermediate neglect of differential overlap (INDO) method... 

The CNDO, INDO, and NDDO Methods. Several semiempirical two-electron MO generalizations of the PPP method were developed that are applicable to both planar and nonplanar molecules. The complete neglect of differential overlap (CNDO) method was proposed by Pople, Santry, and Segal in 1965. The intermediate neglect of differential overlap (INDO) method was proposed by Pople, Beveridge, and... 

The exchange effect due to the electronic spin accounted within the Intermediate Neglect of Differential Overlap (INDO) method (Slater 1960) through considering in Eqs. 1.75 and 1.77 the exchange one-center integrals = K = fiv iiv) is evaluated as... 

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. " ... 

Semiempirical (INDO) approach. Zerner and coworkers developed the semiempirical, Intermediate Neglect of Differential Overlap (INDO) method for the calculation of electronic structures of actinide complexes (Cory et al. 1994). They presented ground-state resonance parameter sets for the actinide elements from Ac to Pu and applied the INDO parameters to the actinide halides, bis(cyclooctatetraenyl) actinide complexes M(COT)2 (M = Th, Pa, U, Np, Pu), the so-called actinocene and imide/amide complexes of uranium. The semiempirical approach is required for large systems, such as biological molecules containing actinide elements. 

---