[Wien] txspec (fwd)

[buero at luitz.at]

On Mon, 18 Aug 2003, Jorissen Kevin wrote:

> 	Joo :In 'txsepc.f' the l -> l+1 transition is calculated first
> and stored into 'X(I,1)'. Then the l -> l-1 transition is calculated
> and stored into 'X(I,2)'. These two transitions have nothing to do
>
> 	Kevin : I'm not familiar with the xspec-code, but I do know
> telnes, which was based on it, and resembles it quite closely.  I
> think you are completely mistaken.  Split DOES split L2 and L3, and


Kevin, that's correct!

txspec only calculates the transitions p_3/2 -> d and p_3/2 -> s. No p_1/2
states are accounted for. When I wrote the progam in 1995 there was the
possibility to select p_3/2 or p_1/2 (by giving the kappa as input to
hfsd.f). However, the differences were so small that I disregarded this.
Also I was told by experimentalists, that what mainly matter with L3/L2
edges is the branching ratio, that is not properly given by theory. The
resulting spectrum add the p_3/2-> (l +/- 1) transitions and adds to this
total image of itself scaled by XINT1/XINT2 (given as input parameter).

The txspec program has not been further developed since 1997. It
was never meant to model anything else but "old day" XANES. It's
successor, "telnes", has many more possibilities and should be used
whenever applicable (although it is much more complex, and many of its
innput parameters are only used for special applications).

However - regarding Joo's comments: if you are interested in optical
properties - you should use neither of these programs, because they both
rely on a well defined separation of core and valence states.

Best
  Joachim

PS: Kevin, a mail to you is still in my "postponed messages" ....



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