Platon TMA analysis

[adam calver]

Hello

I am attempting to interpret a Platon TMA output, and need some advice
with a few points.
If anyone can help I'd be really grateful.

I have refined a structure with TLS parameters in GSAS and am running
it through Platon, as a trial, to make sure I understand the results.
I can reproduce results down to the following sections**, about which
I have 3 questions:

1) Are the T / L Tensors given w.r.t. the Cartesian system or the
Inertial System (or the crystal system)? The numbers are similar
(identical) to those refined by GSAS, so I guess Cartesian... is this
right?

2) What do the Eigenvectors/Values (EVs) of these tensors give? T & L
directions / magnitudes w.r.t. the basis used in 1?

3) The given EVs are stated to be w.r.t. the Inertial System, how are
they calculated?
   I guess it will be something of the form eig(A U A') where A is a
transformation matrix (A' its transpose) and U is the tensor. However,
I have have tried various combinations based on the Inertial
coordinates, but I am obviously missing something.

Thanks in advance
Adam Calver

====================================================================================================================================
Inertial Tensor I, Eigenvectors and Eigenvalues of I in the Cartesian XO,YO,ZO 
System and Angular Relation with X,Y,Z System
------------------------------------------------------------------------------------------------------------------------------------
               XO        YO        ZO          Value              X         Y   
      Z     Origin (Mass-Weighted)
------------------------------------------------------------------------------------------------------------------------------------
I(1)     -0.81405   0.58080   0.00000          99.34          144.49     24.49  
   90.00   X =  0.40040
I(2)     -0.58080  -0.81405   0.00000         101.65          125.51    114.49  
   90.00   Y =  0.36758
I(3)      0.00000   0.00000   1.00000         101.92           90.00     90.00  
    0.00   Z =  0.25000
 
Librational Tensor, L(rad**2)                         Eigenvectors and 
Eigenvalues of L in the Inertial System XI,YI,ZI
------------------------------------------------------------------------------------------------------------------------------------
                                                                  XI        YI  
      ZI         rad**2    Deg**2       Deg
------------------------------------------------------------------------------------------------------------------------------------
 0.00403(  0)   -0.00001(  1)    0.00000(  1)         L(1)  -0.54686   0.83722  
 0.00000        0.00404     13.27      3.64
                 0.00404(  0)    0.00000(  0)         L(2)   0.83722   0.54686  
 0.00000        0.00403     13.22      3.64
                                 0.00157(  0)         L(3)   0.00000   0.00000  
-1.00000        0.00157      5.15      2.27
 
Translational Tensor, T(ang**2)                       Eigenvectors and 
Eigenvalues of T in the Inertial System XI,YI,ZI
------------------------------------------------------------------------------------------------------------------------------------
                                                                  XI        YI  
      ZI          Ang^2            Ang
------------------------------------------------------------------------------------------------------------------------------------
 0.00436(  0)    0.00000(  0)    0.00000(  0)         T(1)  -0.62370   0.78167  
 0.00000        0.00436        0.06604
                 0.00436(  0)    0.00000(  0)         T(2)   0.78167   0.62370  
 0.00000        0.00435        0.06598
                                 0.00300(  0)         T(3)   0.00000   0.00000  
-1.00000        0.00300        0.05480
Cross Tensor, S(rad*Ang)
------------------------------------------------------------------------------------------------------------------------------------
 0.00000(  0)    0.00000(  0)    0.00000(  0)
 0.00000(  0)    0.00000(  0)    0.00006(  0)
 0.00001(  0)   -0.00002(  0)    0.00000(  0)