The shapes of 2s and 2p orbitals are different, an electron has the same energy when it is in the 2s orbital as when it is present in a 2p orbital. The orbitals which have the same energy are called degenerate orbitals, whereas the orbitals which have the same energy are called degenerat...
Atomic orbital energy matching is a valid criterion of bond strength only for half filled molecular orbitals. Doubly occupied molecular orbitals built from atomic orbitals differing in energies may be strongly bonding due to high ionic bond-orders....
In the second set, the2sand2patomic orbitals are constrained to share the same Gaussian exponents. It is shown that this constraint, which produces a significant gain in computational speed in molecular calculations, does not seriously reduce the quality of the atomic orbitals for givenN. A ...
a,b, Single-atom spectrum showing dipole matrix elements d from state 43D (a) and the different mL sublevels (b), highlighting the selection rule for a pair of atoms aligned with the quantization axis. Atomic orbitals for mL = L are represented. c, Two-atom spectrum obtained by dia...
Changes in the mean ionization energy of atoms in compressed matter are estimated through cage models of atomic confinement whereby pressure is obtained in terms of the rate of change of total atomic energy with volume. Resort is taken to a recently implemented shellwise Thomas–Fermi–Dirac–...
Effect of positive-energy orbitals on the configuration-interaction calculation of the HA atom. Phys. Rev. A 43, 1218-1222.Chang T N,Wang R Q.Effect of positive-energy orbitals on the configuration interaction calculation of the H~... Chang,Wang - 《Physical Review A Atomic Molecular & Opt...
of on-site functions obtained from positive ions are found to be far better variationally than those which include virtual (unoccupied) atomic levels: In particular, the inclusion of higher virtual states in the standard LCAO (linear combination of atomic orbitals) basis does not prove convergence...
We demonstrate the accuracy of the self-consistent orthogonalized linear combination of atomic orbitals method within the local-density approximation by applying it to ten different phases of Si. The electronic properties, total energies, and possible structural phase transitions are studied. Also calculat...
It was found, that contracted gaussian functions with scaled exponents lead to good binding energy curves of the hydrogen molecule and that the scaling parameters of the exponents of gaussian functions are very similar to the scaling parameters of the Slater orbitals, mainly for s-type functions.关...
This post explores measuring and optimizing energy usage of multi-node hybrid density functional theory-(DFT) calculations with theVienna Ab initio Simulation Package(VASP). VASP is a computer program for atomic-scale materials modeling, such as electronic structure calculations and quantum-mechani...