 Hello, this is Professor Steven Esheba and I want to take you through how to measure bond strengths in spartan. So what we're going to do, here's just the general outline, we're going to measure the energy in atomic units of the whole molecule that we're interested in, then we're going to measure the energy of its separated pieces, take the difference between them and convert using this conversion factor from atomic units to kilojoules per mole, while we're at it, we'll measure the bond distance and then compare to some literature values. So let's go to this first part, the energy of the molecule, so I'm going to go back to go to spartan now, and let's say the molecule we're interested in is F2, so there it is. Now what you would do as normal is you go here, for since it's a molecule we're going to choose equilibrium geometry, everything else I'll take as default and you'd submit it, in my case it's already been done, so then what you want to do is go to this information bar and here's the critical number of the energy of that molecule in atomic units, and then what we're going to do is we're going to go do the same thing for flooring, the only slight difference is to save yourself some time, you wouldn't do the equilibrium geometry for an atom, you just do the energy, also we have to make sure that we say that flooring has one unpaired electrons, has two because it has an odd number of electrons, then you would submit that, and now there's the energy, once again I've gone up here and I get that, now it's really handy to go and put this into a table, so I've kind of already set this up here, so there's the F2 and there's the F and those are the numbers that I just got, now the difference between them, remember I've got to have the energy of two flooring atoms minus the energy of one flooring molecule, so I'm going to say that's equal to that energy times two, because remember there's two flooring atoms minus that energy, so there we have the result, now this result is in atomic units and I want to convert that into kilojoules, so I'm going to say that's equal to that number and it turns out that 2626 is the conversion, so what we get is that the bond strength of the flooring molecule is 167 kilojoules per mole and I went ahead and looked that up in the literature and that's the value, so it's not done too bad, one other thing is that if you want to find the distance between the bonded pair, I just go here and there and it looks like the distance is about 1.39 and so I'm going to go ahead and put that here, 1.39 electrons and you can see that the literature value is not very different from that. Now the only slight difference here is if you want to get the bond strength between something that's not a homonuclear diatomic or even two fragments, we could do something else, but in this case for the hydroxyl radical OH, I went ahead and did the atomic oxygen, in this case for atomic oxygen I had to specify what's believed that it has two unpaired electrons, so that's what this is, okay, and you can see that I had two unpaired electrons for that one, get an energy, and then same thing for hydrogen and then you go to OH and you get its energy, so in this case I'm just bringing this up because when we go to get the difference what we had to say was it's the difference that is the difference in the separated minus bonded forms is I would have to say oh it's in C10 which is the oxygen plus the energy in C11, that's the hydrogen minus the thing put together, so there's no factor too because I added them all up already, and let's see I think one more thing is in terms of the literature values, you can go anywhere if you like, but here's a place that you can go and get literature values for both the bond enthalpies, which is the same as that we're talking about the bond strengths, and then if it happens that you think that there's double bonds going on then you might compare to that for the literature and then there's the bond lengths, all right.