Subject: Update: plotting MO contours

From: "Dale A. Braden" <[email-masked]>
Date: Mon, 12 Jul 1999 11:51:02 -0700 (PDT)

Dear CCL,

Since posting my summary about making black-and-white MO contour plots
>from Gaussian98 output data (or .cube file or whatever), I got several
additional responses, two of which were particularly helpful in allowing
me to actually create such plots.  If anyone is interested in a way to do
this, I offer one method below.  Again, thanks to all who responded.

A few respondents pointed out that black-and-white plots are automatically
created simply by printing to a black-and-white printer.  In my
experience, the grayscale that results from such an action is not of
publishable quality.  Distinguishing the positive and negative phase of
the contours is best done, I think, using different line types (solid,
dashed, etc.) and thus the ability to control the line type of each
individual contour, as well as its value, is important.  In this respect,
most plotting programs fail. 

One can use the Gaussian cubegen utility or cube=cards keyword to generate
a contour slice through the cube (assuming that the slice you want is
parallel to one face of the cube).  Do this by taking one step of zero
length in one of the directions (you have to take one step or the program
will crash).  Thanks to Timm Lankau for this idea.  A single-line awk
script will then convert the multi-column data into 1-column data which
can be read by a freeware program called Plotmtv (thanks to Iraj Daizadeh
for this suggestion) which can be obtained, among MANY places, from
http://csep2.phy.ornl.gov/csep/PLOTMTV/PLTMTV1.html.  This program is easy
to use and, unlike gnuplot, allows one to control the style of individual
contour lines.  Plotmtv will output a graphical screen image, and a
postscript file. 

Best wishes to all,

Dale

Dale Braden
Department of Chemistry
University of Oregon
Eugene, OR 97403-1253
[email-masked]