Ground-states of atoms

Table 7.1 Ground configurations and ground states of atoms, listed in increasing order of atomic number Z, and their first ionization energies, E...

The angular momentum quantum numbers are often given letter designations, so that when they are stated along with principal quantum numbers, less confusion results. The letter designations of importance in the ground states of atoms are the following ... 

Polarization functions are best defined as atomic orbitals which are not occupied in the ground states of atoms due to symmetry, e.g. p, d orbitals at H or d, f orbitals at O atoms. They provide an additional flexibility of the basis set in the molecule, where the symmetry is significantly lower than in the atom. 

Neglecting spin-orbit contributions (smaller than other relativistic corrections for the ground state of atoms, and zero for closed-shell ones), the Breit hamiltonian in the Pauli approximation [25] (weak relativistic systems) can be written for a many electron system as ... 

Hund s rules are used to determine the ground state of atoms which have electrons in degenerate orbitals, i.e. those with identical energy, such as the three 2p orbitals. These may be stated in the following way in filling a set of degenerate orbitals the number of unpaired electrons is maximized, and such unpaired electrons will possess parallel spins. 

Fig. 1. Hyperfine diagram for the ground state of atomic hydrogen. The high field seeking states a and b can be stabilized in a high magnetic field, while the low field seeking states c and d are trapped in the minimum of a magnetic field...

In this paper we confirm BE s assignment of the 500nm band provide a similar assignment for the 244nm band first observed by BC, and corroborate the Pj Pq designation for the 261.4nm band. The ground state of atomic Pb is Pn(29), with the 3pj multlplet... 

From the theoretical point of view, the electrophilicity concept has been recently discussed in terms of global reactivity indexes defined for the ground states of atoms and molecules by Roy et al.18 19. In the context of the conceptual density functional theory (DFT), a global electrophilicity index defined in terms of the electronic chemical potential and the global hardness was proposed by Maynard et al.20 in their study of reactivity of the HIV-1 nucleocapsid protein p7 zinc finger domains. Recently, Parr, Szentp ly and Liu proposed a formal derivation of the electrophilicity, co, from a second-order energy expression developed in terms of the variation in the number of electrons.21... 

A theoretical expression of the hyperfine structure of the ground state of atomic hydrogen is given in eqn (1) below. Despite the high experimental accuracy of frequency measurement, values of the hydrogen ground state hyperfine structure are principally limited in accuracy at the ppm level by incomplete knowledge of the structure of the finitely-sized proton, represented in eqn. (1) by one term in a sum of various corrections ei [17]. 

The energies of the magnetic interaction of orbital and spin angular momenta are —A and +A/2 in the atomic ion, while they are —A/2, 0, and +A/2 in the molecular ion. Here, A is a spin-orbit coupling constant in the ground state of atomic ion. An additional off-diagonal matrix element arises in the molecular ion from the microscopic spin-orbit operator... 

Now we look in detail at the electronic ground states of atoms with Z = 1 to 10. 

Fig 7 3 Electron configurations in the ground states of atoms of the first ten elements in the periodic table, shown by the method of Fig 7 2... 

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