Detection of Non-Crystallographic Symmetry

PART I: By Self-rotation Function

This program detects NCS from a set of structure factor amplitudes. Number of monomers per asymmetric unit is esmated based on both a reasonable solvent content and NCS detected from self-rotation function.

To use this program online, simply fill the form after reading some breif comments below, and upload a diffraction dataset in either intensity or structure factor amplitude. Results will be returned shortly.

To obtain a license of this program, please contact Renz Research, Inc.

About You


About Your Crystal

a: b: c:
alpha: beta: gamma:
Space group:

for estimate of Matthew's coefficient

Angular error tolerance in degree:
Self-rotation depth:

When crystallographic and non-crystallographic symmetries interact with each other, higher symmetries may be generated and displayed in self-rotation function. The control parameter depth helps to resolve such interaction. The automatically chosen factor works for most cases, however, a user selection may be better. The table below shows the possible options for different space groups:

triclinic 1
monoclinic/orthorhombic 1 2
tetragonal 1 2 4
trigonal/hexagonal 1 2 3
cubic 1 2 3 4

Diffraction data can be either in structure factor amplitude or intensity. Each reflection occupies one record of the file with Miller indices h, k, l, amplitude or intensity and its uncertainty sigma in free format. All records that do not fit this requirement will be ignored.

RRI logo

Renz Research, Inc.
Copyright © 2003 John Zhong Ren
All Rights Reserved