R. McWeeny, Methods of molecular quantum mechanics (Academic Press, London, 1989) and refer-  Home/Search   Document Not in Database   Summary   Related Articles   Check

....Local Density Functional) cannot be successfifily applied, because convergence is extremely difficult to attain, with the charge bouncing between configurations with almost identical energy. For an artificial molecule such as a four dot cell, the Configuration Interaction (CI) technique [5], developed in the field of molecular chemistry, appears to be most appropriate. The many electron wave function is repre sented as a linear combination of Slater determinants onto which the Haniltonian of the problem is projected. The HamiltonJan of our model reads y] h2V 1 , j e2 I ....

R. McWeeny, Methods of molecular quantum mechanics (Academic Press, London, 1989) and refer-

....the diferent regions. On the contrary, the representation of the classical and quantum effects provided by the environment is of paramount importance. Many approximate techniques have been developed to deal with this embedding problem. We have found that the Theory of Electronic Separability (TES) [1,2] provides a rigorous and practical foundation on this problem [3] A hierarchy of approximate cluster in the lattice models can be developed based on the TES formalism. The simplest complete implementation of our ideas, the ab initio Perturbed Ion (aiPI) method [4] has been the germ for a ....

R. McWeeny and B.T. Sutcliffe, Methods of molecular quantum mechanics., (Academic, London, 1969).

....code, while mantaining a friendly user interface. 1 Introduction The ab initio Perturbed Ion method [1, 2] aiPI) is a quantum mechanical method designed to produce an accurate but cheap description of ionic materials. Based on the theory of electronic separability for weakly correlated groups [3, 4], the aiPI method considers each electron group to be tightly bound to a nucleus, thus forming an atom or ion. Effective Hartree Fock equations are succesively solved for each group in the average field created by the rest of the system, and the process is iterated until consistency between all ....

R. McWeeny, Methods of Molecular Quantum Mechanics, Academic Press, London, 2nd edition, 1992.

....user s guide for an expert at control theory that would be curious of knowing more on the models of Quantum Chemistry. A more general and comprehensive introduction can be found for instance in [13, 18, 21, 27, 29, 35] For the theoretical background coming from Quantum Mechanics, we refer to [20, 26] e.g. We only give here a brief overview of the stationary models, without getting into the details nor in the rigorous foundations. The time dependent models will be the topic of Section 4. Let us anticipate on that by saying, somewhat formally, that to figure what a time dependent model is ....

....1 , x n ) 1 # N det(# i (x j ) # i # H 1 (IR 3 , C ) # IR 3 # i # # j = # ij # (23) of H e and in replacing equation (19) by the stationarity condition for the action # T 0 ## e (t) i# t # e (t) H e (t)# e (t) # dt. 24) The associated Euler Lagrange equations [26] read i ## i #t = H## i N # j=1 # ij # j (25) with H# = # M # k=1 z k x k # # N # j=1 # j 2 # 1 x # # N # j=1 # # # j # 1 x # # j . 26) We draw the reader s attention on the fact that, again, this approximation has created nonlinearity. ....

R. McWeeny, Methods of molecular quantum mechanics, 2nd edition, Academic Press, 1992

.... X j;l=1 ( j (Q ) lj ( l (Q 0 ) 51) Z (Q 1 ; Q 0 ; Q f ) Q 1 ; Q ; Q f ) dQ 1 : dQ 1 dQ 1 : dQ f : This shows that ( is similar to the well known one particle density of electronic structure theory [78], and related to a reduced density matrix [79] Note that our density matrix is the transposed of the matrix representation of the density operator in the set of the single particle functions. Diagonalising the operator ( yields the natural populations and natural orbitals [27,28,47,80] ....

R. McWeeny, Methods of Molecular Quantum Mechanics (Academic Press, London, 1989).

....Local Density Functional) cannot be successfully applied, because convergence is extremely difficult to attain, with the charge bouncing between configurations with almost identical energy. For an artificial molecule such as a four dot cell, the Configuration Interaction (CI) technique [5], developed in the field of molecular chemistry, appears to be most appropriate. The many electron wave function is represented as a linear combination of Slater determinants onto which the Hamiltonian of the problem is projected. The Hamiltonian of our model reads H = Gamma X i h 2 2m r ....

R. McWeeny, Methods of molecular quantum mechanics (Academic Press, London, 1989) and references

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McWeeny, J., 1992, Methods of Molecular Quantum Mechanics. Academic Press, New York (2nd Ed.)

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