Multiconfiguration self-consistent field theory

This chapter begins with a discussion of how to include non-dynamical and dynamical electron correlation into the wave function using a variety of methods. Because the mathematics associated with correlation techniques can be extraordinarily opaque, the discussion is deliberately restricted for the most part to a qualitative level an exception is Section 7.4.1, where many details of perturbation theory are laid out - those wishing to dispense with those details can skip this subsection without missing too much. Practical issues associated with the employ of particular techniques are discussed subsequently. At the end of the chapter, some of the most modem recipes for accurately and efficiently estimating the exact correlation energy are described, and a particular case study is provided. 

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Gilbert, T. L. (1972). Multiconfiguration self-consistent-field theory for localized orbitals. I. The orbital equation. Phys. Rev. A6, 580-600. 

II. Second-order Direct Multiconfiguration Self-consistent Field Theory... 

II. SECOND-ORDER DIRECT MULTICONFIGURATION SELF-CONSISTENT FIELD THEORY... 

Roothaan, C. C. J., Detrich, J. H. (1983). General quadratically convergent multiconfiguration self-consistent-field theory in terms of reduced matrix elements. Phys. Rev. A 27,9-56. 

Bak KL, J0rgensen P, Helgaker T, Ruud K, Jensen HJAa (1993) Gauge-origin independent multiconfigurational self-consistent-field theory for vibrational circular dichroism. J Chem Phys 98 8873-8887... 

Abstract. The title paper is reviewed in perspective of the later development of computational methods in quantum chemistry. The importance of the concept of natural spin orbitals is discussed and its implication for the future development of multiconfigurational self-consistent-field theories is illustrated. 

K. L. Bak, P. Jorgensen, T. Helgaker, K. Ruud, and H. J. A. Jensen, /. Chem. Phys., 98,8873 (1993). (jauge-Origin Independent Multiconfigurational Self-Consistent-Field Theory for Vibrational Circular Dichroism. 

Heislbetz S, Rauhut G (2010) Vibrational multiconfiguration self-consistent field theory Implementation and test calculations. J Chem Phys 132 124102... 

Figure 3 A schematic illustration on how the exact quantum limit can be reached through either the multitrajectory approach or a multiconfiguration self-consistent field theory. Correction terms e (t) are introduced to reach the SCF-limit retaining a trajectory concept...

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