Complete active self-consistent field

One of the drawbacks of DFT is its inability to treat multiconfigurational problems properly. In these cases, some type of configuration interaction (Cl) method is needed [60], Ideally, one would like to carry out full Cl calculations, but this is generally not possible for practical reasons. Thus, some kind of approximation is needed and, in this respect, the so-called complete active self-consistent field (CASSCF) procedure is often used. [Pg.138]

Roos B O 1987 The complete active space self-consistent field method and its applications in electronic structure calculations Adv. Chem. Phys. 69 399-445... [Pg.2200]

Complete active space self-consistent field... [Pg.124]

Anderson K, Malmqvist PA, Roos BO (1992) Second-order perturbation-theory with a complete active space self-consistent field reference function. J Chem Phys 96 1218... [Pg.329]

It is evident that the approach described so far to derive the electronic structure of lanthanide ions, based on perturbation theory, requires a large number of parameters to be determined. While state-of-the-art ab initio calculation procedures, based on complete active space self consistent field (CASSCF) approach, are reaching an extremely high degree of accuracy [34-37], the CF approach remains widely used, especially in spectroscopic studies. However, for low point symmetry, such as those commonly observed in molecular complexes, the number of CF... [Pg.15]

Asymptotic analysis, electronic states, triatomic quantum reaction dynamics, 317—318 Azulene molecule, direct molecular dynamics, complete active space self-consistent field (CASSCF) technique, 408-410... [Pg.68]

Density functional theory, direct molecular dynamics, complete active space self-consistent field (CASSCF) technique, non-adiabatic systems, 404-411 Density operator, direct molecular dynamics, adiabatic systems, 375-377 Derivative couplings conical intersections, 569-570 direct molecular dynamics, vibronic coupling, conical intersections, 386-389 Determinantal wave function, electron nuclear dynamics (END), molecular systems, final-state analysis, 342-349 Diabatic representation ... [Pg.74]