 Hello, this is Professor Steven Esheba and I'm just getting started with using Spartan through VDesk. So I've set it up here at vdesk.putasound.edu and I'm going to click here on the right hand side. You might have to enter some login identities when you do this, but eventually you'll get to this screen here and it will take us to a menu and it's Spartan's student up there that we want. So I've just double clicked on that and now what will happen normally when you come up, when you first start Spartan, there's a few option settings you might want to allow. One of them is this called preferences and under preferences I'm going to say I want a few icons. One of them is this thing called the new build. Another one is that I want to measure distances and another one is I want to edit build and that's what I'm going to say apply there and the other option is that I want to actually see those icons. So when you save it should, when you launch this again it should all show up again. So I'm going to go to this new build icon now and it's handy to use this inorganic menu and I just want to click this one line here which means what will happen is that when I select an atom here, which I'm going to start with say argon, it will default to having one hydrogen on it, which I'm going to have to delete, but now I've double clicked in that space, I've double clicked in that space, I have two argon atoms and I want to get rid of the hydrogen so I click right on the tip there, click right on the tip there. So now I have two argon atoms and that's not really actually as big as we think that they are so I'm going to go to the space filling mode under model. That's a little bit closer and what are the radii? Well we think that argon, I've gone to this Wikipedia page for Van der Waals radius and there's argon. Now these numbers are given in hundreds of angstroms so this says that a single argon atom has a radius of like 1.88 or 1.9 angstroms and so that would be say almost you know almost two angstroms for those radii. Now are argon atoms attracted to each other? Well in fact they kind of are and you can find that out by pressing this minimize button which says if you are attracted to each other then go toward that point and well looks like they are not attracted to each other at this distance, maybe they're too far away so what I'm going to do is go to this measure distance icon and what I have to do is click on each of these and I'm seeing that the distance is 11 angstroms away maybe if I put them five angstroms away by doing that then now I'm going to try the minimizer again and say are you attracted and yeah they are and one more thing that we can do with this is I'm going to go back to this measure distance. How far apart are they? Well they are 3.7 angstroms apart and if you remember the radius of a single argon atom is something like you know almost two angstroms then that means the distance between these centers it makes sense that it would be not quite four angstroms because it's one radius and another radius and so and you can do these with this with other atoms don't forget to select the space filling model. Sometimes you might want to go to this model icon here and sorry to the edit one and say I'd like to center it that's kind of handy sometimes too and if you want to go to a different atom or even a different molecule go to new build there in this case let's suppose I wanted there's some pre-built one so there's methane right there and I can double click on this one double click on this one once again go to space filling that's what two methane molecules look like you can still do the same distance measurement in this case I'm just going to see are they attracted to each other based on this distance and perhaps not but if I bring a little bit closer maybe they will be so if I bottom five angstroms will they be now attracted to each other and indeed they are.