Thanks a lot. Yes, but I need to calculate exact value of dielectric function because I want to obtain SPR (surface plasmon resonances) and LSPR peak when the particle’s polarizability is maximized. For a spherical particle, this condition is satisfied when imaginary part of dielectric is small and real part is 2 times permittivity of surrounding medium. Therefore different selections of volume factor can change SPR.
Regards, Eliya On Mon, May 4, 2015 at 8:13 PM, Guangping Zhang <[email protected]> wrote: > Dear Eliya Asmani, > > This is because, in SIESTA, the dielectric function is reciprocal to the > volume of the supercell. So, you need to use the same supercell. Or you can > multiply the volume of the supercell for each job and then divided by a > same volume factor at last. > > Kind regards, > > /Guangping Zhang > > > On 2015/5/4 13:16, Eliya Asmani wrote: > >> Dear all >> >> I calculated imaginary part of dielectric function for a metal cluster >> with different radius 0.5, 1 and 1.5 nm. As you know in the siesta for open >> system, supercell should be determined. My results are dependent on size of >> supercell and with increasing radius of cluster, size of supercell >> increases and value of dielectric function decreases while I don't expect >> this behaviour. >> >> What is the unit of permittivity in siesta I think it isn't dimensionless. >> >> >> I appreciate if anyone has the same experience help me to solve this >> problem. >> >> Regards >> >> >> > >
