Ideas of Quantum Chemistry P87 ppt

... astrophysi- cist, professor at the Stock- holm University, originator of the electrolytic theory of ionic dissociation, measurements of the temperature of plan- ets and of the solar corona, also of the theory ... billions of variables in the game describing the degrees of freedom of the water molecules in the first and further hydration shells. One of the important steps to...

Ngày tải lên: 06/07/2014, 09:20

... abyss of the sea without a bottom. 22 The presence of the Dirac sea makes the Dirac the- ory, in fact, a theory of an infinite number of particles, whereas formally it was only a theory of a single ... CALCULATION OF THE GROUND STATE OF THE HYDROGEN-LIKE ATOM WITHIN DIRAC THEORY Matrix form of the Dirac equation We will use the Dirac equation (3.59). First, the basis set compos...

Ngày tải lên: 06/07/2014, 09:20

... disposal all the necessary solutions of eq. (5.16). The eigenfunctions of the ˆ H (0) operator appeared as a consequence of using them as the complete set of functions (e.g., in expanding ψ (1) k ). ... ψ k (λ) are analytical functions of λ (p. 205). In this mathematical aspect of the physical problem we may treat λ as a complex number. Then the radius of convergence ρ of the...

Ngày tải lên: 06/07/2014, 09:20

... describe future vibrations of the molecule (changes of R) as well as its rotations (changes of the direction of R). A simple analogy Let us stop for a while to catch the sense of the adiabatic approximation. To ... PES, for the motion of the nuclei, rep- resents one of the most important ideas in chemistry. This concept makes possible contact with what chemists call the spati...

Ngày tải lên: 06/07/2014, 09:20

... has to be convex as a function of the positions of the nuclei. 6. Please choose the wrong answer. As a result of the rotational excitation J → (J +1) of a molecule of length R: a) the angular momentum ... func- tion in the form of a product of an electronic function and a function describing the motion of the nuclei; c) leads to the notion of the potential energy curve for t...

Ngày tải lên: 06/07/2014, 09:20

... a function of the configuration of the nuclei. Our motivation is as follows: • economy of computation: ab initio calculations of the electronic energy for larger molecules would have been many orders of ... oligopeptide the num- ber of conformations is of the order 36 of 10 20 , and for a hundred amino acids – 35 Wijnand Schepens, PhD thesis, University of Gand, 2000. 36 The...

Ngày tải lên: 06/07/2014, 09:20

... bond One of the molecules is a donor, the other is an acceptor of a proton, Fig. 7.10.a. A local minimum of smaller stability appears when one of the water molecules serves as a donor of two protons, ... 7.10.a): • stretchingofthehydrogenbondO–H O(thevibrationoftwowatermolecules treated as entities): 183 cm −1 • bendingofthehydrogenbondO–H Ointheplaneofthefigure:345cm −1 • bendingoft...

Ngày tải lên: 06/07/2014, 09:20