Multiconfigurational quantum methods

Transition Metal- and Actinide-Containing Systems Studied with Multiconfigurational Quantum Chemical Methods... 

Shepard R (1987) In Lawley KP (ed) Ab initio methods in quantum chemistry part II the multiconfiguration SCF method. Wiley, Chichester... 

Shalashilin DV (2010) Nonadiabatic dynamics with the help of multiconfigurational ehrenfest method improved theory and fully quantum 24d simulation of pyrazine. J Chem Phys 132(24) 244111... 

Gaghardi, L. and Roos, B. O. 2007. Multiconfigurational quantum chemical methods for molecular systems containing actinides. Chem. Soc. Rev. 36 893-903. 

Classical Dynamics of Nonequilibrium Processes in Fluids Integrating the Classical Equations of Motion Control of Microworld Chemical and Physical Processes Mixed Quantum-Classical Methods Multiphoton Excitation Non-adiabatic Derivative Couplings Photochemistry Rates of Chemical Reactions Reactive Scattering of Polyatomic Molecules Spectroscopy Computational Methods State to State Reactive Scattering Statistical Adiabatic Channel Models Time-dependent Multiconfigurational Hartree Method Trajectory Simulations of Molecular Collisions Classical Treatment Transition State Theory Unimolecular Reaction Dynamics Valence Bond Curve Crossing Models Vibrational Energy Level Calculations Vibronic Dynamics in Polyatomic Molecules Wave Packets. 

Electron-Molecule Scattering Mixed Quantum-Classical Methods Path Integral Methods Photodissociation Dynamics Rates of Chemical Reactions Reaction Path Hamiltonian and its Use for Investigating Reaction Mechanisms Reactive Scattering of Polyatomic Molecules Time-dependent Multiconfigurational Hartree Method. 

Roos BO, Andersson K, Fulscher MP, Malmqvist PA, Serrano-Andres L, Pierloot K, Merchan M (1996) Multiconfigurational perturbation theory applications in electronic spectroscopy. In Pri-gogine I Rice SA (eds) New methods in computational quantum mechanics, Vol. 93 of Advances in Chemical Physics, Wiley, New York, p 219... 

The methods used to describe the electronic structure of actinide compounds must, therefore, be relativistic and must also have the capability to describe complex electronic structures. Such methods will be described in the next section. The main characteristic of successful quantum calculations for such systems is the use of multiconfigurational wave functions that include relativistic effects. These methods have been applied for a large number of molecular systems containing transition metals or actinides, and we shall give several examples from recent studies of such systems. 

Nonrelativistic quantum chemistry has been discussed so far. But transition metal (starting already from the first row) and actinide compounds cannot be studied theoretically without a detailed account of relativity. Thus, the multiconfigurational method needs to be extended to the relativistic regime. Can this be done with enough accuracy for chemical applications without using the four-component Dirac theory Much work has also been done in recent years to develop a reliable and computationally efficient four-component quantum chemistry.25,26 Nowadays it can be combined, for example, with the CC approach for electron correlation. The problem is that an extension to multiconfigurational... 

With the development of powerful computers, these methods have been restricted in practice to the application in specific problems where no other calculations are available. For non-relativistic atomic systems, they have been replaced by quantum mechanical calculations like Monte Carlo or multiconfigurational Hartree-Fock ones. Nevertheless, Thomas-Fermi estimates can be easily evaluated by non-specialists in theoretical calculations and in some problems they provide a starting point for more sophisticated procedures. Moreover, they are interesting for theoretical purposes such as finding relationships among different average quantities [4]. 

H.-J. Werner, Matrix-Formulated Direct Multiconfiguration Self-Consistent Field and Multiconfiguration Reference Configuration-Interaction Methods, in Ab Initio Methods in Quantum Chemistry - II (K.P. Lawley, ed.), John Wiley Sons Ltd, Chichester (1987). 

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