ИСТИНА

Contemporary quantum chemistry is obcessed by «monistic machinism» - the idea that all molecules and chemical events has to be calculated by one big program in a single approximation valid for all times and nations. No other idea is more uncongenial for chemistry than this due to enormous diversity of physical conditions occurring in different molecules or in different parts of one molecule. It is not even clear how such a immature idea could come to the clever heads of the leaders of the scientific public opinion. Even in those cases when the differences between the parts of a molecular system is recognized they are totaly irrelevantly formulated as "interesting" and ''unintersting". By contrast our vision of segmentation of a molecular system is based on analysis of physical conditions as manifested through the localization of spectral and chemical events: transitions between electronic states occur in chromophores; respectively, only one or two bonds are broken or formed at once. This chemical picture has no counterpart in contemporary quantum chemistry paradigm reducing to a sequential addition of corrections to Hartree-Fock approximation having by itself quite a limited chemical relevance. Pushing off from this we in last years developed a new concept of semi-empirism in quantum chemistry based on the idea of chromophores formalised by the McWeeny's group functions and the Löwdin partition technique employed to treat the boundary conditions between the groups. The efficiency of the numrical tools based on this concept is reached by targeting each method to a specific class of problems or objects in contrast with “universal” and thus inefficient methods. Each targeted code is based on singling out chromophores characteristic for a target class of molecules and applying methods of problem solving relevant for each chromophore. Among the methods developed along these lines are: ECF - effective crystal field method for analysis of electronic structure and spectra of transition metal complexes; SLG - linear growth group of methods for analysis of electronic structure, heats of formation, geometry, and ionization potentials of organic molecules; CATALYST - implementation of the effective Hamiltonian method for analysis of electronic structure of catalytic transition metal complexes; ECFMM - hybrid QM/MM method for analysis of PES of transition metal complexes; DMM - sequential derivation of classical model of PES for organic molecules and QM/MM interfaces. These methods have been extensively tested on objects which due to their complexity or size could not be studied by standard QM or MM methods. Publications on the methods and application examples are available at http://www.qcc.ru/tch. The computer codes can be used through the NetLaboratory portal at http://www.qcc.ru/netlab. Examples of their applications will be given.