[comp.parallel] Spectral Code ideas

kelly@think.com (Kelly Pickard) (05/22/91)

  I forwarded the article to one of the people I
  work with for his comments, listed below.  Additionally,
  TMC is working on a pentadiagonal solver that will be
  included in a future release of the CMSSL (CM Scientific
  Software Library).

  Regards,
    Kelly Pickard
    Thinking Machines Customer Support

------

   Regarding this spectral problem, I have no experience with 
   penta-diagonal solvers, but it seems to me that the calculation 
   would be order nx*ny, whereas the FFT in nx*ny*ln(ny). This
   seems to indicate that the FFT will dominate his calculations.
   He should try weighting the y axis so his fft is mostly on 
   processor, and compare that to the generic layout performance.

							Rich

   ------- Forwarded Message

   Date:    Fri, 17 May 91 15:02:36 -0400 
   From:    kurt@Think.COM
   To:      science@Think.COM
   Subject: spectral code request


   from comp.parallel:
   Article 2604 (1 more) in comp.parallel (moderated):
   From: jek@cs.duke.edu (James E. Kittock)
   Subject: Pseudospectral codes on the CM-II...
   Date: 16 May 91 18:50:50 GMT

....

chasman@athena.mit.edu (David Chasman) (05/23/91)

Umm,
I and my co-authors have spectral code up and running on the CM.
3-D is currently being coded.
Refs:
@ARTICLE{cmachine:1:chasman-silbey,
	AUTHOR = " David Chasman and Robert J. Silbey and Michael Eisenberg",
	TITLE = { Massively Parallel Time Dependent Wave-Packet Calculations
                  in a Classically Chaotic Potential},
	JOURNAL = { Chem. Phys. Lett.},
	YEAR = { 1990 },        
	VOLUME = { 175 },
	NUMBER = { 6 },
	PAGES = { 633-640 },
	MONTH = { Dec. },
}
For a little more detail, we have a paper currently in press in Theoretica
Chimica Acta , soon to be published:

\title{\large\bf Massively Parallel High Energy \\
  Time Dependent Wave-Packet Calculations \\
  Prepared for : Theoretica Chimica Acta \\
  Parallel Computing for Chemical Reactivity \\
  Perugia, Italy \\
  August 31 - September 1 , 1990 
}
   (same authors as above )

Finally, we are finishing off a 3-D release of our code using the
Chebeychev propogator of Kosloff et. al. in CM-fortran which will
be ready at the end of june.  For wave-packet people, this will allow
you to just plug in a potential and an initial condition.

If you want details and/or papers drop me a line

       David Chasman
       MIT 6-230
       Cambridge MA 02139
       USA

       PHONE: (617) 253-1538  (work)
       FAX:   (617) 253-7030