It could be found in many tddft book, e.g., "Fundamentals of time-dependent density functional theory". I'm afraid I misunderstood dielectric function as the microscopic one. Anyway you should be able to find those relations in the book.
Best regards, Pu Zhang -- Postdoc The group of Structured Electromagnetic Materials Department of Photonics Engineering Technical University of Denmark Ørsteds Plads, Building 345v, 166 2800, Kgs. Lyngby E-mail: [email protected] Homepage: http://www.dtu.dk/Service/Telefonbog/Person?id=91944&tab=0 Phone: 45 25 36 43 Fax: 45 93 65 81 On Wed, Mar 26, 2014 at 7:23 PM, zgp121 <[email protected]> wrote: > Dear Zhang, > > Thanks for your joining into the discuss. Can you give some literatures on > how to calculate the dielectric function based on the polarizability of a > cluster system? And do you know the unit of the data in Systemlabel.EPSIMG? > > I think, in siesta, the dielectric function is calculated using the fomula > of polarizability, not a weighted averge. > > With best regards. > > Guangping > > 2014-03-26 > ------------------------------ > ------------------------------ > *发件人：*Pu ZHANG <[email protected]> > *发送时间：*2014-03-26 15:39 > *主题：*Re: [SIESTA-L] dielectric function in SIESTA > *收件人：*"siesta-l"<[email protected]> > *抄送：* > > Hi, Guangping > > In general, polarizability is weighted average of dielectric function over > the whole object under study. I'm not familiar with SIESTA per se, but I > don't think dielectric function is a simple data structure to easily store > and output, so I guess probably you are right about the Systemlabel.EPSIMG. > > Best regards, Pu Zhang > -- > Postdoc > The group of Structured Electromagnetic Materials > Department of Photonics Engineering > Technical University of Denmark > Ørsteds Plads, Building 345v, 166 > 2800, Kgs. Lyngby > E-mail: [email protected] > Homepage: http://www.dtu.dk/Service/Telefonbog/Person?id=91944&tab=0 > Phone: 45 25 36 43 > Fax: 45 93 65 81 > > > On Wed, Mar 26, 2014 at 3:00 PM, zgp121 <[email protected]> wrote: > >> Dear all, >> >> Can anyone tell me the relationship between the dielectric function and >> the polarizability for the molecular system in SIESTA code? >> >> I think the data stored in Systemlabel.EPSIMG is the frequency-dependent >> polarizability not dielectric function. Or can someone give some formula >> used in SIETA optical calculation. I can not find the explicit documented >> relationship between the dielectric function and polarizability in SIESTA. >> >> >> Thanks in advance. >> >> Guangping >> >> 2014-03-26 >> ------------------------------ >> > >
