[Wien] muffin tin approximation

[Peter Blaha]

>  Yes. a self-consistent 'old fashion' MT potential is
> what I need. I hope the potential is a constant in the
> interstitial region . What will wien2k do for
> interstitial region if 'V-NMT' in case.in1 is 0?
> Can we turn off the full potential?

There are various "versions" of "muffin-tin" calculations:

One can make MT only for the potential (i.e. in the Hamiltonian), but
keep the full density, or make "double"-MT (this is what was done the old
days) and have, both, V and rho in MT form.

WIEN is not designed to make a double MT calculation, since our solver
for the potential needs a Fourier expansion in the interstitial.

The closest to the double MT is:

In case.in2: remove all higher LM terms, keep only LM=0 0
However, you MUST keep a good GMAX!

Before running lapw1 you must change case.vns(up/dn).
Set "NUMBER OF PW     1"  to 1 in this file (use a "sed" command to
change this automatically in run_lapw; or if you are more familiar with
fortran, write only ONE PW in lapw0.F (at the very end of this program)

This runs a "double" MT inside the sphere, while in the interstitial the
density is "warped", but the potential is constant (MT).

PS: I have very much doubt that making a MT calculation is meaningfull
(except for "educational" reasons). It is similar as saying: I want to make a
"bad" calculation or I want to use RKMAX=2 and see what comes out.

Regards


                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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