The electronic properties of graphene
... 2007兲. It has also been suggested that Coulomb interactions are considerably enhanced in smaller geometries,
such as graphene quantum dots 共Milton Pereira et al.,
2007兲, leading to unusual Coulomb blockade effects
共Geim and Novoselov, 2007兲 and perhaps to magnetic
phenomena such as the Kondo effect. ...
Ultracold chemistry of a single Rydberg atom in a rubidium
... interacts with the surrounding neutral atoms. Due to the large extension of the
Rydberg electron wave function, a large amount of neutral atoms are present
inside the Rydberg electron orbit. This mainly leads to two different effects
based on the polarizability of the neutral atoms. On the one hand, ...
... depth typically necessary to be able to apply the techniques to computational
problems. When possible, the chapter ends with a list of steps to be taken for
There are many good books describing the fundamental theory on which
computational chemistry is built. The description of that t ...
Resolution-of-identity approach to Hartree–Fock, hybrid
... surfaces, nano-structures, etc) from first principles play an important role in chemistry and
condensed-matter research today. Of particular importance are computational approximations
to the many-body Schrödinger or Dirac equations that are tractable and yet retain quantitatively
reliable atomic-s ...
... of interactions near Feshbach resonances was of limited applicability due to rapid losses.
Feshbach resonances were used mainly to access molecular states of dimers and trimers.
In contrast, for fermions, losses are heavily suppressed (see below), and so most of this
review focuses on strongly inter ...
Theory of ultracold atomic Fermi gases
... with the study of spin polarized configurations with an
unequal number of atoms occupying two different spin
states. In particular, the Clogston-Chandrasekar limit,
where the system loses superfluidity, has been experimentally identified at unitarity 共Shin et al., 2006兲. These
configurations provide ...
TrajectoryBased Nonadiabatic Dynamics with TimeDependent
... Until this point, the formulation was kept as general as possible and did not depend on a particular choice of the electronic structure method used to solve the time-dependent
Schrçdinger equation for the electrons. In many cases, it is
however convenient to map the set of Equations (14) and (15)
The Thomas-Fermi model: momentum expectation values
... Within the Thomas-Fermi model including the exchange interaction and contributions of strongly
bound electrons, analytical expressions are obtained for all momentum expectation values pb> and for some
of the expectation values of powers of the electron density pm> for an atom with an arbit ...
Relativistic effects in atomic and molecular properties
... atoms move rather slowly, at a mere of one percent of light speed. Thus it is that a satisfactory description of the atom can be obtained without Einstein’s revolutionary theory.” Possibly
these beliefs were initiated by Dirac himself , who wrote in 1929 that ”Relativistic effects are
therefore o ...
Chapter 5: Optical Processes in Semiconductors
... The 2-level system exchanges energy with the EM-field of frequency ω only if the photon energy E=ħω=E2-E1 (resonance)
1) electrons in the ground state E1 absorb a photon and make an up-ward transition to the excited (upper) state E2.
2) electrons in the excited state E2 make a down-ward transition t ...
Density functional theory and nuclear quantum effects
... I), and nuclear quantum effects (Part II).
Kohn-Sham density functional theory (KSDFT) is by far the most widely used
electronic structure theory in condensed matter systems. The computational time
of KSDFT increases rapidly with respect to the number of electrons in the system,
which hinders its pr ...
The roles of electronic exchange and correlation in charge
... The charge-transfer-to-solvent 共CTTS兲 reactions of solvated atomic anions serve as ideal models for
studying the dynamics of electron transfer: The fact that atomic anions have no internal degrees of
freedom provides one of the most direct routes to understanding how the motions of solvent
Elliptic Preconditioner for Accelerating the Self
... Fermi–Dirac function evaluated at εi . When β is suﬃciently large, the Fermi–Dirac
function behaves like a step function that drops from 1 to 0 at μ (which lies between
εN and εN +1 ). Spin degeneracy is omitted here for simplicity.
In this paper, we assume the Kohn–Sham system (1.1) is deﬁned withi ...
Physical Chemistry 2nd Edition
... many-electron problem.
The Hartree-Fock energy may be written as
E HF ET EV E J EK
where ET = kinetic energy
EV = the electron–nuclear potential energy
EJ = Coulomb
EK = interaction energy
L-edge X-ray absorption study of mononuclear vanadium complexes
... orbit coupling (SOC) interaction between the potentially many
final state multiplets. The SOC interaction dominates the
spectral appearance and is responsible for the splitting into
distinct L3 and L2 edges. Therefore, L-edge spectra cannot, in
general, successfully be interpreted on the basis of a ...
Chapter 1 The Kondo screening cloud: what it is and
... experiments. This is simply the magnetic polarization of the electrons as
a function of distance from the impurity, in linear response to a magnetic
field (applied to both the impurity and the conduction electrons). The
second (Sub-Section 1.2.2) is the charge density (Friedel) oscillations, as a
The Propagators for Electrons and Positrons 2
... Diagram 2.2e represents the scattering of an electron originating at x moving forward in time, experiencing several scatterings, and ending up at x . Along its way
from x to x a pair is produced by a potential acting at x1 ; the two created particles
propagate forward in time. The positron of th ...
Density functional theory
Density functional theory (DFT) is a computational quantum mechanical modelling method used in physics, chemistry and materials science to investigate the electronic structure (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. Using this theory, the properties of a many-electron system can be determined by using functionals, i.e. functions of another function, which in this case is the spatially dependent electron density. Hence the name density functional theory comes from the use of functionals of the electron density. DFT is among the most popular and versatile methods available in condensed-matter physics, computational physics, and computational chemistry.DFT has been very popular for calculations in solid-state physics since the 1970s. However, DFT was not considered accurate enough for calculations in quantum chemistry until the 1990s, when the approximations used in the theory were greatly refined to better model the exchange and correlation interactions. In many cases the results of DFT calculations for solid-state systems agree quite satisfactorily with experimental data. Computational costs are relatively low when compared to traditional methods, such as Hartree–Fock theory and its descendants based on the complex many-electron wavefunction.Despite recent improvements, there are still difficulties in using density functional theory to properly describe intermolecular interactions (of critical importance to understanding chemical reactions), especially van der Waals forces (dispersion); charge transfer excitations; transition states, global potential energy surfaces, dopant interactions and some other strongly correlated systems; and in calculations of the band gap and ferromagnetism in semiconductors. Its incomplete treatment of dispersion can adversely affect the accuracy of DFT (at least when used alone and uncorrected) in the treatment of systems which are dominated by dispersion (e.g. interacting noble gas atoms) or where dispersion competes significantly with other effects (e.g. in biomolecules). The development of new DFT methods designed to overcome this problem, by alterations to the functional and inclusion of additional terms to account for both core and valence electrons or by the inclusion of additive terms, is a current research topic.