StudentShare solutions
Triangle menu

Quantum - Coursework Example

Nobody downloaded yet
Consequently, LDA is generally related to functionals, which are based on HEG approximation. LDA are implemented in realistic systems measurements and calculations (for example, molecules and solids). In a general view, for a spin-unpolarized system, “LDA for the exchange-correlation energy is the following where ? refers to the electronic density and ?xc, the exchange-correlation energy concentration, is a function of the density. The exchange-correlation energy is split into exchange and correlation terms in a linear view: thus separate expressions for Ex and Ec are defined. Separate expressions known for the correlation density lead to numerous different approximations for ?c”. (Parr and Weitao, 1994) LDA is a part of any approximate exchange-correlation functional. Its main function is to “replicate direct results of the HEG for non-varying densities” (Parr and Weitao 1994, p. 35). As a result, LDA is often mentioned as an explicit component of such kind of functional. The Perdew-Burke-Ernzerhof (PBE) Modern scientists and researchers are greatly concerned about updating GGA functionals in their implementation in molecules and solids. ...
Currently, accents in “generalized gradient approximations are shifted toward the description of free-atom energies” (Perdew et al, 2008). A group of scientists, Perdew et al (2008) have transformed and “adapted the Perdew-Burke-Ernzerhof generalized gradient approximation that updates equilibrium characteristics of dense solids and their surfaces” (Perdew et al, 2008). It is relevant to underline that the Perdew-Burke-Ernzerhof is a widely-used tool in solid state calculations. Consequently, a relevant note is that PBE is currently transformed with regard to GGA implementing both the density and its gradient at every space point (Perdew et al, 2008). If to correlate both concepts GGA and PBE, it will be clearly seen that GCA counterbalances “computational efficiency, numerical accuracy, and reliability” (Perdew et al 2008, p. 4068). Moreover, “PBE refers to the demands of quantum chemistry and solid-state physics” (Perdew et al 2008, p. 4068). Modern scientists think that it is necessary to ‘widen horizons’ of PBE implementation. Thus during the last decade it has been found out that “PBE reduces the chronic overbinding of the local spin density approximation (LSDA) [1], but, while LSDA often slightly underestimates equilibrium lattice constants by about 1%, PBE usually overestimates them by about the same amount” (Perdew et al 2008, p. 4070). Moreover, another important point of PBE properties is its equilibrium properties (e.g. bulk moduli, phonon frequencies, magnetism, and ferroelectricity). The abovementioned properties are susceptible to the lattice constant; thus they are ‘overcorrected’ by PBE (Perdew et al, 2008). Moreover, in spite of the fact that LSDA defines low ...Show more


Quantum Local-density approximation (LDA) Local-density approximations and the Perdew-Burke-Ernzerhof generalized gradient approximation are widely used by physicists and chemists for electronic structure investigation of different body-systems. Local-density approximations (LDA) refer to “a certain class of approximations implemented to the exchange-correlation (XC) energy functional in  DFT, which are dependant on electronic density value at each point in space” (Parr and Weitao, 1994)…
Author : murraycandida
Quantum essay example
Read Text Preview
Save Your Time for More Important Things
Let us write or edit the coursework on your topic
with a personal 20% discount.
Grab the best paper

Check these samples - they also fit your topic

International Oil and Gas Law
Introduction Colonel Drake can be said to be the father of the oil & gas industry as it was he who made the first successful drilling at Titusville, Pennsylvania on 27 August 1859. At the end of the First World War, petroleum was declared as necessary for the economy of a nation as blood is to the human body.
16 pages (4000 words) Coursework
Quantum in physics
(Belloni et al, 2005)This theory briefly states the following 1. Energy comes in tiny but distinct units and is never continuous. 2. The particles forming the energy unit acts as particles and waves. 3. The motions of these particles are haphazard. 4. The position and momentum of a particle cannot be measured at the same time.
4 pages (1000 words) Coursework
U09a1 Universe Review
Dark energy is not directly observed, but rather inferred from observations of gravitational interactions between astronomical objects, along with dark matter. Dark matter must exist to account for the gravity that holds galaxies together. Dark matter is also responsible for amplifying small fluctuations in the cosmic microwave background back in the early universe to create the large scale structure we observe in the universe today.
3 pages (750 words) Coursework
The Character of Physical Law
The principle of locality states that an object is influenced by its immediate location. The principle is instrumental in quantum mechanics to studies phenomenon that cannot be explained by Newtonian mechanic. Locality is a realism property, which asserts that an objects needs not to be visible for it to be in action (Louisa, 2008).
3 pages (750 words) Coursework
Abuse of Legal & Ilegal drugs
The likelihood of drug abuse amongst rural teenagers is greater than that of their city dwelling counterparts. A variety of drugs are being abused, in order to pander to the cravings of these juvenile addicts. This study, which had been
2 pages (500 words) Coursework
Henry V/White Paper
Management is usually about agreeing with the views of experts in different fields of organizational operations for the better results. Sometimes managers find it hard to accept the points of others but the
4 pages (1000 words) Coursework
U09a1 Universe Review
Dark matter must exist to account for the gravity that holds galaxies together. Dark matter is also responsible for amplifying small
3 pages (750 words) Coursework
Executive Remuneration Principles and practice
This was one of the primary topics for financial economists. According to the comparative analysis, it is evident that there were few of the fundamental needs as well as general judicial principles came into light
10 pages (2500 words) Coursework
In this paper, the works of seven philosophers and how their works shaped contemporary education and contemporary thoughts are discussed. As
7 pages (1750 words) Coursework
An advanced treatment of lasers and their applications
2. Lasers light emit light that is very directional.  Laser light is emitted as a comparatively narrow beam in a given direction. In
6 pages (1500 words) Coursework
Hire a pro to write
a paper under your requirements!
Win a special DISCOUNT!
Put in your e-mail and click the button with your lucky finger
Your email
Comments (0)
Click to create a comment
Let us find you another Coursework on topic Quantum for FREE!
Contact us:
Contact Us Now
  • About StudentShare

  • Testimonials

  • FAQ

  • Blog

  • Free Essays
  • New Essays
  • Essays

  • The Newest Essay Topics
Join us:
Contact Us