CHEMISTRY GLOSSARY
Results 1–5 of 5 for rhombohedral
rhombohedral crystal system → romboedarski kristalni sustav
Rhombohedral crystal system is also known as the trigonal system. The crystallographic axes used in this system are of equal length. None of the axes are perpendicular to any other axis.
a = b = c
α= β = γ ≠ 90°
rhombohedral lattice → romboedarska rešetka
Rhombohedral (or trigonal) lattice has one lattice point at the each corner of the unit cell. It has unit cell vectors a=b=c and interaxial angles α=β=γ≠90°.
crystal system → kristalni sustav
Crystal system is a method of classifying crystalline substances on the basis of their unit cell. There are seven unique crystal systems. The simplest and most symmetric, the cubic (or isometric) system, has the symmetry of a cube. The other six systems, in order of decreasing symmetry, are hexagonal, tetragonal, rhombohedral (also known as trigonal), orthorhombic, monoclinic and triclinic.
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Crystal system
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Unit-cell
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Conditions on unit-cell edges and angles |
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cubic |
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a=b=c α=β=γ=90° |
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hexagonal |
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a≠c α=γ=90° β=120° |
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tetragonal |
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a=b≠c α=β=γ=90° |
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rhombohedral |
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a=b=c α=β=γ≠90° |
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orthorhombic |
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a≠b≠c α=β=γ=90° |
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monoclinic |
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a≠b≠c α=γ=90°≠β |
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triclinic |
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a≠b≠c α≠β≠γ≠90° |
Bravais lattice → Bravaisova rešetka
Bravais lattice is a set of points constructed by translating a single point in discrete steps by a set of basis vectors. The French crystallographer Auguste Bravais (1811-1863) established that in three-dimensional space only fourteen different lattices may be constructed. All crystalline materials recognised till now fit in one of these arrangements. The fourteen three-dimensional lattices, classified by crystal system, are shown to the bottom.
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Crystal system
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Bravais lattices
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cubic a=b=c α=β=γ=90° |
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simple cubic
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body-centered cubic
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face-centered cubic
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tetragonal a=b≠c α=β=γ=90° |
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simple tetragonal
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body-centered tetragonal
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orthorhombic a≠b≠c α=β=γ=90° |
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simple orthorhombic
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base-centered orthorhombic
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body-centered orthorhombic
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face-centered orthorhombic
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monoclinic a≠b≠c α=γ=90°≠β |
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simple monoclinic
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base-centered monoclinic
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hexagonal a=b≠c α=β=90° γ=120° |
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hexagonal
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rhombohedral a=b=c α=β=γ≠90° |
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rhombohedral
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triclinic a≠b≠c α≠β≠γ≠90° |
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triclinic
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Citing this page:
Generalic, Eni. "Rhombohedral." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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