Symmetry adapted functions for double point groups II. Cubic point groups

1970 ◽  
Vol 67 (3) ◽  
pp. 647-656 ◽  
Author(s):  
A. P. Cracknell ◽  
S. J. Joshua

AbstractA method of deriving the basis functions of the double-valued representations of a point group by the reduction of Kronecker products is described. The method has been used to derive expressions for these bases for cubic point groups for which the results are tabulated.

1969 ◽  
Vol 65 (2) ◽  
pp. 567-578 ◽  
Author(s):  
Arthur P. Cracknell

AbstractBasis functions are derived and tabulated for the double-valued representations of the triclinic, monoclinic, orthorhombic, trigonal, tetragonal and hexagonal crystallographic point groups using the method of projection operators.


1966 ◽  
Vol 21 (11) ◽  
pp. 2400-2408 ◽  
Author(s):  
Yositaka Onodera ◽  
Makoto Okazaki

Author(s):  
Peter J. Knowles

AbstractWe present a new approach for the assignment of a point group to a molecule when the structure conforms only approximately to the symmetry. It proceeds by choosing a coordinate frame that minimises a measure of symmetry breaking that is computed efficiently as a simple function of the molecular coordinates and point group specification.


2019 ◽  
Vol 36 (7) ◽  
pp. 2237-2243
Author(s):  
Cyril F Reboul ◽  
Simon Kiesewetter ◽  
Dominika Elmlund ◽  
Hans Elmlund

Abstract Motivation No rigorous statistical tests for detecting point-group symmetry in three-dimensional (3D) charge density maps obtained by electron microscopy (EM) and related techniques have been developed. Results We propose a method for determining the point-group symmetry of 3D charge density maps obtained by EM and related techniques. Our ab initio algorithm does not depend on atomic coordinates but utilizes the density map directly. We validate the approach for a range of publicly available single-particle cryo-EM datasets. In straightforward cases, our method enables fully automated single-particle 3D reconstruction without having to input an arbitrarily selected point-group symmetry. When pseudo-symmetry is present, our method provides statistics quantifying the degree to which the 3D density agrees with the different point-groups tested. Availability and implementation The software is freely available at https://github.com/hael/SIMPLE3.0.


Pramana ◽  
1989 ◽  
Vol 32 (6) ◽  
pp. 721-730
Author(s):  
K Rama Mohana Rao ◽  
N Nirmala
Keyword(s):  

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