[ESPResSo] bug in random.tcl in mbtools

[Jacob Kirkensgaard]

Hi all mbtools users

In the file random.tcl in the mbtools package the following lines are  
found

        # Now choose a random orientation vector.  Actually it's not
        # strictly random if we do it like this (fix)
        lappend orient [expr [t_random]]
        lappend orient [expr [t_random]]
        lappend orient [expr [t_random]]


I think replacing with these lines should fix it:

        lappend orient [expr 2*[t_random]-1]
        lappend orient [expr 2*[t_random]-1]
        lappend orient [expr 2*[t_random]-1]

This means we are now sampling all directions in space instead of only  
the cone consisting of vectors with positive coordinates.

Best,
Jacob Kirkensgaard
Copenhagen University