The ABINIT Users Mailing List ( CLOSED )

[Xavier Gonze <gonze@pcpm.ucl.ac.be>]

Dear Javier Lopez,

Javier Lopez wrote:
> Dear ABINIT users,
> In the log file of some relaxation processes (ionmov not 0),
> the inverse hessian is written at the end of the log file. I think I 
> understand the way it is written (first all the atomic coordinates, then 
> the strain components) but I'm not sure about the units.
> Are fractional coordinates used or rather cartesian coordinates?
> (I have in mind extracting information about some gamma-point
> frequencies from this matrix).

If you have in mind extracting gamma-point frequencies, I suggest
strongly that you use the linear-response part of ABINIT : the
Hessian matrix is quite approximate, and useful only for the
purpose of speeding the convergence ! On the contrary,
the linear-response part of ABINIT is quite accurate and well-tested,
please see the Tutorial number 5 ...

Good continuation,
Xavier Gonze