Quantum chemistry and its “ages”

The Ages and Chemistry of the Oldest Stellar Halo Populations

NGST is capable of reaching the main sequence turnoff of the oldest stellar populations (MV = +4.5) out to a distance ≈ 2 Mpc. There is now evidence that the oldest, most metal poor star clusters are coeval to within 1 Gyr over a 200 kpc radius centered on the Milky Way. NGST can be used to make an equally definitive test of this in the halo and globular cluster system of M31, NGC 147, 185, and...

Schrodinger Equation and Quantum Chemistry

π and its computation through the ages

Understanding the nature of the constant π, as well as trying to estimate its value to more and more decimal places has engaged a phenomenal energy from mathematicians from all periods of history and from most civilizations. In this small overview, we have tried to collect as many as possible major calculations of the most famous mathematical constant, including the methods used and references ...

Voltage-Controlled Entanglement between Quantum- Dot Molecule and its Spontaneous Emission Fields via Quantum Entropy

The time evolution of the quantum entropy in a coherently driven threelevel quantum dot (QD) molecule is investigated. The entanglement of quantum dot molecule and its spontaneous emission field is coherently controlled by the gat voltage and the intensity of applied field. It is shown that the degree of entanglement between a three-level quantum dot molecule and its spontaneous emission fields...

Orbitals in Quantum Chemistry

Orbitals, on the one hand, are often considered as auxiliary quantities without physical meaning for various reasons. Slater determinants, e.g., Hartree-Fock or Kohn-Sham determinants, are invariant with respect to unitary transformations of the occupied orbitals. Within densityfunctional theory (DFT) orbitals frequently are considered as quantities that merely generate the electron density but...