When imposing non-analytical term to dynamical matrix, Born effective
charges and permittivity read from this file. In fropho, the
non-analytical term is implemented following
Eq. (3.20) that is given in atomic unit. The first
line is the factor that the non-analytical term is multiplied with,
and this value is used to adjust the unit system, i.e., if you use
VASP code, you have to change the unit system from atomic unit to eV
and Å, which might be
. The dielectric
constant written in the second line. The continuous lines are the Born
effective charges of independent atoms which are displaced. One line
represents one Born effective charge tensor. The order of the lines of
the permittivity and Born effective charge is given by xx, xy, xz, yx,
yy, yz, zx, zy, zz in Cartesian coordinates. The matrix elements in
each tensor should be symmetrized by your hand. The number of
effective charges (lines) required is determined by fropho. It is easy
to check by dry-run, e.g.,
`NDIM = 1 1 1`

, `LSUPER = .TRUE.`

and `IRPINT = 2`

, and
see the line ``independent atom'' in standard output.
example

14.400
2.00 0.00 0.00 0.00 2.00 0.00 0.00 0.00 2.00
1.98 0.00 0.00 0.00 1.98 0.00 0.00 0.00 1.98
-0.99 0.00 0.00 0.00 -0.99 0.00 0.00 0.00 -0.99
...

togo
2009-02-12