Thanks to Dr. Bob Hanson and Dr. Angel Herráez for their very helpful advice about this.
The problem was that, on a page displaying MOs for teaching purposes, I was offering both a translucent orbital surface, produced using the mo command, and a two-dimensional contour plot on a plane through the orbital, produced using the isosurface command. It was the isosurface command which was taking most of the time. Thus, for the pi_nb_in_plane HOMO orbital (mo 16) of BF3 in https://www.staff.ncl.ac.uk/bruce.tattershall/teaching/maingrps/bf3mo/bf3.php Chrome using the HMTL5.0 JSmol option took 5 seconds to produce the 3D orbital surface but 16 seconds to produce the 2D line contour plot. (This speeds up to 3 s and 10 s respectively on the more powerful PCs our U provides for student class use.) I took the suggestion of calculating the surface immediately after loading the model, but waiting for the student to request the contour plot by clicking a Jmol button. I also took the suggestion to put in echoes to tell the user what they were waiting for in each case. Although the two representations are each calculated in less than 2 seconds using the Java Jmol option in Java enhanced IE11, I think that, for students stuck with using a browser without Java, then a 3 - 5 second initial wait is tolerable if they are given information about what is happening. The original offering of a 13 - 21 second unexplained wait was putting such students off. Bruce (original post 20 March 2017) ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Jmol-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jmol-users

