Converts anisotropy and asymmatry representation of a 3x3 interaction tensor into the corresponding matrix.
Isotropic part, anisotropy, and asymmetry are often seen in the literature. It is not a good way of reporting an interaction tensor (the original matrix is best), but it is still being used.
iso - isotropic part of the interaction, defined as (xx+yy+zz)/3 in terms of eigenvaues an - interaction anisotropy, defined as zz-(xx+yy)/2 in terms of eigenvalues as - interaction asymmetry, defined as (yy-xx)/(zz-iso) in terms of eigenvalues alp - alpha Euler angle in radians bet - beta Euler angle in radians gam - gamma Euler angle in radians
M - 3x3 matrix
The reverse transformation (from matrix into anisotropy, asymmetry, and angles) is ill-defined.
Version 2.1, authors: Ilya Kuprov