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(Freqeuncy dependent RespOnse function Generator)
@@ Toshiaki IITAKA www.iitaka.org
FROG is a group of programs based on the Projection Method (Kernel Polynomial Methods) [1] for calculating linear respose function with amazing efficiency. This method is can be and has been applied to nanosctructres [2], Anderson localization models [3] and quantum spin systems at finite temperatures [4,5]. The executable program contained in this package is a particular version developed for calculation of quantum spin systems on WindowsXP machine. In the future, programs for other problems on other machines will be included in this package as a united program and/or a group of sister programs.

[1] T. Iitaka, S. Nomura, H. Hirayama, XW. Zhao, Y. Aoyagi, T. Sugano,  Calculating the linear response functions of noninteracting electrons with a time-dependent Schrodinger equation, Phys. Rev. E 56, 1222-1229 (1997). (journal) (preprint)
[2] S. Nomura, T. Iitaka,  XW. Zhao, T. Sugano, Y. Aoyagi,  Linear scaling calculation for optical-absorption spectra of large hydrogenated silicon nanocrystallites, Phys. Rev. B 56, R4348-R4350 (1997). (journal)
[3] T. Iiitaka, Fast Algorithm for Quantum Physics, RIKEN Review No.19, 136-143 (1998). (journal)
[4] T. Iitaka, T. Ebisuzaki, Algorithm for linear response functions at finite temperatures, Application to ESR spectrum of s=1/2 antiferromagnet Cu benzoate. Phys. Rev. Lett. 90, 047203 (2003).  (journal) (preprint)
[5] M. Machida, T. Iitaka and S. Miyashita, Temperature dependence of ESR intensity for the nanoscale molecular magnet V15, J. Phys. Soc. Jpn. Suppl. 74, 107-110 (2005). (preprint) (journal)
[6] Manabu Machida, Toshiaki Iitaka, Seiji Miyashita, "The ESR intensity and the Dzyaloshinsky-Moriya interaction of the nanoscale molecular magnet V15", Phys. Rev. B 86, 224412 (2012).  (journal, preprint)

Download Package HERE. (zip,368KB)

Other References
FROG's Family
Shitaro Nomura (Tsukuba Univ.)
Hiroshi Tanaka (Shimane Univ.)
Manabu Machida (Univ. Tokyo)
Koji Maruyama (RIKEN)