Calculate the inertia tensor and transforms along rotation axes.

This function calculates the inertia tensor and returns a 4-tuple.

The unit is amu * length-unit-of-xyz-file**2

Returns:The returned dictionary has four possible keys:

transformed_Cartesian: A Cartesian that is transformed to the basis spanned by the eigenvectors of the inertia tensor. The x-axis is the axis with the lowest inertia moment, the z-axis the one with the highest. Contains also a column for the mass

diag_inertia_tensor: A vector containing the ascendingly sorted inertia moments after diagonalization.

inertia_tensor: The inertia tensor in the old basis.

eigenvectors: The eigenvectors of the inertia tensor in the old basis. Since the inertia_tensor is hermitian, they are orthogonal and are returned as an orthonormal righthanded basis. The i-th eigenvector corresponds to the i-th eigenvalue in diag_inertia_tensor.

Return type:dict