Muffin-tin approximation Muffin-tin approximation The muffin-tin approximation is a shape approximation of the potential well in an crystal lattice. It is most commonly employed in quantum mechanical simulations of the electronic band structure in solids. The approximation was proposed by John C. Slater. Augmented plane wave method (APW) is a method which uses muffin-tin approximation. It is a method to approximate the energy states of an electron in a crystal lattice. The basic approximation lies in the potential in which the potential is assumed to be spherically symmetric in the muffin-tin region and constant in the interstitial region. Wave functions (the augmented
Diplomatic gift A 2012 gift of a "British" table tennis table to President Obama seemed ideal until it was revealed that it was designed in Britain but made in China, evoking worries about the decline of British manufacturing industry. Diplomatic gifts take diverse forms: Diplomatic gift A diplomatic gift is a gift given by a diplomat, politician or leader when visiting a foreign country. Usually the gift is reciprocated by the host. The use of diplomatic gifts dates back to the ancient world and givers have competed to outdo each other in the lavishness of their gifts. Examples include silks given to