planar set
81Projective transformation — A projective transformation is a transformation used in projective geometry: it is the composition of a pair of perspective projections. It describes what happens to the perceived positions of observed objects when the point of view of the… …
82Hypergraph — An example hypergraph, with X = {v1,v2,v3,v4,v5,v6,v7} and E = {e1,e2,e3,e4} = {{v1,v2,v3}, {v2,v3} …
83Crystal field theory — (CFT) is a model that describes the electronic structure of transition metal compounds, all of which can be considered coordination complexes. CFT successfully accounts for some magnetic properties, colours, hydration enthalpies, and spinel… …
84Orcus (Dungeons & Dragons) — Orcus Game background Title(s) Prince of the Undead, Prince of Undeath, The Blood Lord Home plane Abyss Power level Demon lord Alignment …
85List of NP-complete problems — Here are some of the more commonly known problems that are NP complete when expressed as decision problems. This list is in no way comprehensive (there are more than 3000 known NP complete problems). Most of the problems in this list are taken… …
86Pentax K mount — The Pentax K mount, sometimes referred to as the PK mount , is a lens mount standard for mounting interchangeable photographic lenses to 35 mm single lens reflex (SLR) cameras. It was created by Pentax in 1975, [cite web | url =… …
87Degeneracy (graph theory) — In graph theory, a k degenerate graph is an undirected graph in which every subgraph has a vertex of degree at most k: that is, some vertex in the subgraph touches k or fewer of the subgraph s edges. The degeneracy of a graph is the smallest… …
88Point location — The point location problem is a fundamental topic of computational geometry. It finds applications in areas that deal with processing geometrical data: computer graphics, geographic information systems (GIS), motion planning, and computer aided… …
89Molecular geometry — Geometry of the water molecule Molecular geometry or molecular structure is the three dimensional arrangement of the atoms that constitute a molecule. It determines several properties of a substance including its reactivity, polarity, phase of… …
90Molecular symmetry — in chemistry describes the symmetry present in molecules and the classification of molecules according to their symmetry. Molecular symmetry is a fundamental concept in chemistry, as it can predict or explain many of a molecule s chemical… …
