[Wien] Murnaghan

[Stefaan Cottenier]

To the WIEN authors:

In case.outputeos, an expression for the Murnaghan equation is given as:

E=B*V/BP*(1/(BP-1)*(V0/V)**BP +1)

However, this is not the equation which is used inside the code (and which
is found in the literature), which is:

E=E0+[B*V/BP*(1/(BP-1)*(V0/V)**BP +1)-B*V0/(BP-1)]/14703.6

(a term E0, a term B*V0/(BP-1) and a factor 1/14703.6 were missing). The
expression for the pressure P=B/BP*((V0/V)**BP -1) seems to be OK, apart
from the same factor 1/14703.6 (needed to convert the bulk modulus from GPa
to atomic units).

To avoid confusion, it would be better to put the correct expressions either
in case.outputeos or in the UG.

Stefaan