Ortho is a PHP script that allows orthogonalization of unit cell parameters [1] via SVD (singular value decomposition) [2] of specific matrix. Whole process is described during calculation.

To calculate unit cell identity parameters Π [1] you can use SimΠ script.


  1. L. Fábián, A. Kálmán: Acta Cryst. B 55 (1999) 1099-1108.
  2. K. Baker: "Singular Value Decomposition Tutorial", The Ohio State University (2005).