CRYSTAL is a
quantum chemistry
Quantum chemistry, also called molecular quantum mechanics, is a branch of physical chemistry focused on the application of quantum mechanics to chemical systems, particularly towards the quantum-mechanical calculation of electronic contributions ...
''
ab initio
( ) is a Latin term meaning "from the beginning" and is derived from the Latin ("from") + , ablative singular of ("beginning").
Etymology
, from Latin, literally "from the beginning", from ablative case of "entrance", "beginning", related t ...
'' program, designed primarily for calculations on crystals (3 dimensions), slabs (2 dimensions) and polymers (1 dimension) using
translational symmetry
In physics and mathematics, continuous translational symmetry is the invariance of a system of equations under any translation (without rotation). Discrete translational symmetry is invariant under discrete translation.
Analogously, an operato ...
, but it can also be used for single molecules.
[''Computational Chemistry'', David Young, Wiley-Interscience, 2001. Appendix A. A.2.2 pg 334, Crystal] It is written by V.R. Saunders, R. Dovesi, C. Roetti, R. Orlando, C.M. Zicovich-Wilson, N.M. Harrison, K. Doll, B. Civalleri, I.J. Bush, Ph. D’Arco, and M. Llunell from Theoretical Chemistry Group at the
University of Torino
The University of Turin (Italian language, Italian: ''Università degli Studi di Torino'', UNITO) is a public university, public research university in the city of Turin, in the Piedmont (Italy), Piedmont region of Italy. It is one of the List ...
and the Computational Materials Science Group at the
Daresbury Laboratory
Daresbury Laboratory is a scientific research laboratory based at Sci-Tech Daresbury campus near Daresbury in Halton, Cheshire, England. The laboratory began operations in 1962 and was officially opened on 16 June 1967 as the Daresbury Nuclea ...
near
Warrington
Warrington () is an industrial town in the Borough of Warrington, borough of the same name in Cheshire, England. The town sits on the banks of the River Mersey and was Historic counties of England, historically part of Lancashire. It is east o ...
in
Cheshire
Cheshire ( ) is a Ceremonial counties of England, ceremonial county in North West England. It is bordered by Merseyside to the north-west, Greater Manchester to the north-east, Derbyshire to the east, Staffordshire to the south-east, and Shrop ...
, England. The current version is CRYSTAL23. Earlier versions were CRYSTAL88, CRYSTAL92, CRYSTAL95, CRYSTAL98, CRYSTAL03, CRYSTAL06, CRYSTAL09, CRYSTAL14, and CRYSTAL17.
Program structure
The program is built of two modules: ''crystal'' and ''properties''. The ''crystal'' program is dedicated to perform the
SCF calculations, the geometry optimizations, and the frequency calculations for the structures given in input. At the end of the SCF process, the program crystal writes information on the crystalline system and its wave function as unformatted sequential data in
Fortran unit 9, and as formatted data in Fortran unit 98.
One-electron properties and wave function analysis can be computed from the SCF wave function by running the program ''properties''.
The main advantage of the crystal code is due to the deep and optimized exploitation of symmetry, at all levels of calculation (SCF as well gradients and vibrational frequencies calculations). This allows significant reduction of the computational cost for periodic calculations. Note that while the symmetry generally reduces to identity in large molecules, large crystalline system usually show many symmetry operators.
See also
*
Crystal structure
In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat ...
*
Mercury
*
Quantum chemistry programs
References
External links
CRYSTALComputational Materials Science GroupTheoretical Chemistry Group
University of Torino
{{DEFAULTSORT:Crystal
Computational chemistry software