A quantum mechanical study showed that the presence of Er atoms in the PT structure favors a transition from tetragonal to cubic that reduces the tetragonality (c/a) generated by a small disturbance in the energy levels of the atomic orbitals
within the structure [1, 17].
So we can conclude that the stability of atomic orbitals
is not an experimental indication of a need for quantum gravity.
Use of gaussian expansions of slater-type atomic orbitals
," The Journal of Chemical Physics, vol.
Silverstone, "Analytical evaluation of multicenter integrals of r 12-1 with Slater-type atomic orbitals
. V.four-center integrals by Fourier-transform method," The Journal of Chemical Physics, vol.
For example, it is possible to visualise the atomic orbitals
, see electronic effects using arrows and identify bond lengths and element symbols.
summation is carried out over all atomic orbitals
at a given atom, i.e.
The stepping approach, introduced in  from an interpretation of numerical data, treats the process as scattering on individual independent electrons occupying atomic orbitals
and suggests that the cross section follows the free-electron behavior in (8) and 9) down to T equal to the ionization threshold for the orbital and that below that energy the electron on the corresponding orbital is "deactivated" thus producing a sharp "step" in the dependence of the cross section on T.
The above configurations are based on the energies of the atomic orbitals
of Cd and Se which have been calculated using Hartree-Fock method .
Auger transition Atomic orbitals
Kinetic energy (eV) [N.sub.4][O.sub.2][P.sub.1] [4d.sub.3/2]-[5p.sub.1/2]-6s 74.5 [N.sub.4][O.sub.3][P.sub.1] [4d.sub.3/2]-[5p.sub.3/2]-6s 76.5 [N.sub.5][O.sub.2][P.sub.1] [4d.sub.5/2]-[5p.sub.1/2]-6s 71.5 [N.sub.5][O.sub.3][P.sub.1] [4d.sub.5/2]-[5p.sub.3/2]-6s 73.5
A SZP basis set is employed to describe the localized atomic orbitals
. The core electrons are modeled with Troullier and Martins  nonlocal pseudopotential.
The molecular wave function is constructed according to the LCAO (Linear Combination of Atomic Orbital
) method in which molecular orbitals are obtained as a linear combination Slater-type atomic orbitals