Subject: Summary: Fortran for Irix 6.x

From: Christian Klein <[email-masked]>
Date: Fri, 03 Oct 1997 08:29:47 -0500

Thanks to all who responded! 

Here is the outcome: 

SGI does provide Fortran compilers for the latest Irix versions. Both
f77 and f90/95 compilers can be bought as part of a package (MIPSpro
Compilers package), which also includes C and C++. Some responders
acknowledged the good performance of these compilers. 

From a conversation with an SGI sales representative, however, I
concluded that the cheapest solution for our lab will cost at least
$1500, and probably twice as much. 

Free, or cheaper, compilers do not seem to be available.
 
Konrad Hinsen wrote that he used to work with f2c and did not experience
any trouble, although the generated code is somewhat slower than the one
from "genuine" Fortran compilers. The problem with our source is, that
it is quite large and we hope that a recompilation with a genuine
Fortran compiler works smoother than the f2c, so we can get along with
fewer changes. 

Chris

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From: "Peter Shenkin" <[email-masked]>
Date: Fri, 3 Oct 1997 11:07:51 -0400

On Oct 3,  8:29am, Christian Klein wrote:
> Subject: CCL:Summary: Fortran for Irix 6.x

If your institution joins the SGI Varsity program, you can get the
compilers and more for much, much less.  I forget the exact numbers....

	-P.

-- 
******************* Jimmy Witherspoon, 1923 - 1997, RIP *******************
* Peter S. Shenkin; Chemistry, Columbia U.; 3000 Broadway, Mail Code 3153 *
** NY, NY  10027;  [email-masked];  (212)854-5143;  FAX: 678-9039 ***
*MacroModel WWW page: http://www.columbia.edu/cu/chemistry/mmod/mmod.html *

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From: "Omar G. Stradella" <[email-masked]>
Date: Fri, 03 Oct 1997 12:38:17 -0400

> Fortran compiler works smoother than the f2c, so we can get along with

Hi Chris,

I'm almost sure that UIC is a member of the Varsity Program, if that's
the case you can try to get in contact with the "contact" person in your
University to see if you can get the compiler from them. For more
datails about the Varsity Program, check:

http://www.sgi.com/silicon_campus/varsity_NA.html

Hope this hels,

Omar.
-- 
+---------------------------------------------------------------------+
Omar G. Stradella, Ph.D.                    Supercomputing Applications 
Silicon Graphics, Inc.                          Computational Chemistry
One Cabot Road, Hudson, MA 01749, USA           N 42 22'41" W 71 33'45"
E-mail: [email-masked] Phone: +1-978-567-2258 FAX: +1-978-562-4755 
http://www.sgi.com/ChemBio                  http://reality.sgi.com/omar 
+--------  Ph-nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn  -------+

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From: Konrad Hinsen <[email-masked]>
Date: Fri, 3 Oct 1997 18:36:29 +0200

> Fortran compiler works smoother than the f2c, so we can get along with

Maybe it's worth pointing out what f2c really is and does. It is based
on a genuine Fortran compiler, the first one available for Unix
systems, and which has been the basis for some Fortran 77 compilers
offered by various manufacturers. Due its "generic Unix" origin,
the code generator was a well isolated and easily replacable piece.
f2c is nothing but a version of this Fortran compiler with a code
generator that spits out C code. So f2c is as much a Fortran compiler
as any other; it supports the full Fortran 77 standard.

The reason why f2c + a C compiler is usually less efficient than a
direct Fortran compiler is that some optimization approaches are lost
due to the intermediate representation as C code. The Fortran standard
contains some rules that enable important optimization (at the cost of
reliability) which C code does not permit. And Fortran has optimizable
built-in numerical operations where C uses a library approach which
makes optimization more difficult (though not impossible).

So if speed is not of extreme importance, f2c can be a fully
sufficient replacement for a Fortran compiler.
-- 
-------------------------------------------------------------------------------
Konrad Hinsen                          | E-Mail: [email-masked]
Laboratoire de Dynamique Moleculaire   | Tel.: +33-4.76.88.99.28
Institut de Biologie Structurale       | Fax:  +33-4.76.88.54.94
41, av. des Martyrs                    | Deutsch/Esperanto/English/
38027 Grenoble Cedex 1, France         | Nederlands/Francais
-------------------------------------------------------------------------------

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From: Ning Xie <[email-masked]>
Date: Fri, 03 Oct 1997 18:41:54 -0600 (CST)

Good day! cclers,
We are using Gaussian 94 calculating the energy of the complex formed
between permanganate
and ZnCl2. We suppose that ZnCl2 is tetrahedral with two chloride atoms,
an oxygen atom from permangate ion and another oxygen atom from acetone
(solvent) as ligands. We want to keep the geometry of permanaganate ion
tetrahedral. But after optimization, three oxygen atoms and manganese are
almost on the same plane and the remaining oxygen atom joins acetone
(CH3COCH3--->CH3COCH2OH). I tried to fix the geometry of permanganate ion
as tetrahedral by defining its bond lengths and bond angles as constant at
the start of the calculation. It doesn't seem to be working. Is there
somebody out there who would give me a hint?
Thank you very much for your help.
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