 approximately 20 minutes, and best would be if you live around five minutes for question. Thank you. Okay, so hi everybody, I'm Marcia Apuvic-Juivari, and today I want to talk about the ultrafast dynamic of photo-excited DNA bases in base pair investigated with a fragment diabolization linear ironic coupling model. And DNA has a strong absorption in UV region, but the existence of the fast non-radiative decay prevents the DNA from the photo damage. Here we want to study this photo chemical and photo physical process that causes strong self-protection of the DNA against this photo damage. So if we want to study the DNA, it's better that first of all we concentrate on building black after DNA. So now we want to study the cytosine, guanine, adenine, and time in which they are building black after DNA. The molecule in the equilibrium situation is in the ground, the state, but up on the excitation the molecule gained the energy of the photon and goes to the higher state, which we call them excited state. So the molecule, my voice is too high or not? For me, it's okay, but they're clear than. Okay. So the molecule in each excited state has different energy, different electron orientation, different shape. So what happened when we have this absorption? We have an electron configuration of the ground state. So we have, this is our electron configuration, but up on the excitation, up on the excitation, for example, this electron gained the energy and we have a new configuration, which this is excited state configuration. Mathematically speaking, the molecular orbital is a mathematical function which describes the location and the behavior of an electron in a molecule. If we want to name this molecular orbital, we call them, for example, the highest occupied molecular orbital, we call them HOMO and the lowest unoccupied molecular orbital, we call them LOMO. So the other molecular orbital, we call them HOMO minus one, HOMO minus two, LOMO plus one, and LOMO plus one, blah, blah. So, and here each circle shows the electron in the molecular orbital. So by up on the excitation, electron in occupied molecular orbital gained the energy and goes to the unoccupied molecular orbital, which here you can see this is a HOMO to LOMO transition. In total, when we are talking about the excited state, the excited state are divided in two categories. One of them is the brightest state that this state are a state that can absorb or emit light. And so, for example, a pi pi star state is a kind of the brightest state. And the other category is a darker state that this state cannot absorb or emit a photon or light. And the n pi star state or pi Riedberg state, they are kind of the darker state. So now I want to specify what is this n pi star state because I want to, in our conclusion, you can see something about this n pi star state. So we want, I told you that we want to study cytosine, adenine, tymin, and iguanine. But if, for example, if you take a look to the cytosine, here you can see that we have a lone pair of nitrogen and oxygen here. So this lone pair can enter to this transition. So excited state, which arise from this lone pair of nitrogen or oxygen, we call them dark n pi star state. And specifically, we call them dark n o pi star state or dark n n pi star state. So this is the definition of the dark n pi star state. And the other thing that I want to clarify for you is that I told you that non-radiative decay prevent the DNA from the photo damage. So what is this non-radiative decay? So I told you that the molecule in an equilibrium situation is in a ground state. But up in the excitation, the molecule gained energy of the photon goes to the excited state. Then this molecule can come back to the ground state by emitting the light. But the other possibility is that this molecule moves in this potential energy surface. But when the molecule reach here where two potential energy surface, they touch each other, there's a two possibility of a molecule. One possibility is to continue to going in this way. The other possibility is to come back in a lower state, which now here is our ground state. This process in total, we call them non-radiative decay because there's no radiation. We do not see any emits of the photon. And this non-radiative decay happened here, which we call it conical intersection, that the conical intersection is a place that two potential energy surface touch each other. For example, here you can see this conical intersection. So in my study, I want to study this non-radiative decay process with the full quantum dynamic approach. What it means? Up to now, people use the semi-classical approach to study this excited state behavior of the single base, in which in a semi-classical approach, they are using some initial trajectory. They let this initial trajectory move classically. But by a statistic, how they move, they study the system. But in my case, I want to study with full quantum dynamic approach. It means that I want to describe the molecule with this wave packet. It means that we don't know the exact position of the molecule. And in a quantum dynamic approach, instead of using the Hamiltonian equation of motion, we use the Schrodinger recursion. And the other difference between the quantum dynamic approach and semi-classical approach is that when we are in a semi-classical approach, we just have one molecule. The molecule is moving. But when we move to the quantum dynamic approach, we don't have just one molecule. We should take care of all possible motion of the molecule. For example, here we have water. So we have three different possible motions. So as the number of the atom in a molecule increases, the number of this vibrational mode or possible motion of the atoms in a molecule increases. So computationally, this quantum dynamic approach is high cost for us. Anyway, to run this dynamic. So if we want to run the quantum dynamic approach to study this exactly, to study this excited state behavior, we cannot use the quantum dynamic approach for this surface. Because here it's a strong coupling. We have unharmonicity. And we cannot use the quantum dynamic approach. So instead of this surface, we move to other surface, which we call them diabetic surface. This is adiabatic surface, and this is diabetic surface. The diabetic surface is now you can see it's more or less it's simple. It's too parabola. And so here it's more it's a bit simpler for us. So we call them diabetization moving from here to here we call them diabetization. For this study, we are using the linear vibronic coupling Hamiltonian. What it means, this is our Hamiltonian linear vibronic coupling Hamiltonian. This is a kinetic term. This is potential term. And this is the coupling. And in linear vibronic coupling Hamiltonian, our coupling is a linear function of the coordinate to is a coordinate. And this is the linear function of the coordinate. So the idea is here we can see that when we move a bit, suddenly our potential energy surface change a lot. But here it is more or less it is not a strong change in a potential. So we need a state. The idea is that we need a state that this is they do not change with the coordinate. So we should have some reference a state. So what is our reference a state, we take the reference a state as an adiabatic a state in a frankendom point. So the idea of this diabetization to to obtain this diabetic a state and in the term of the adiabatic a state in a reference point, which here we show it by zero in a frankendom point. So then we want to obtain this rotational matrix that give us the diabetic a state in term of the adiabatic a state. In order to obtain this rotational matrix, we just displace the molecular geometry along each dimension and its normal coordinate. And then we obtain this rotational matrix. When we have this rotational matrix, we can obtain the energy. And then this coupling, which is our linear coupling, we just we can just obtain it from the numerical differentiation. So this is our linear vibronic coupling Hamiltonian. In my calculation or electronic calculation where performed using Gaussian 16, we use a can be truly functional with 631 plus GDP basis set and a linear vibronic coupling model obtained by diabetization based on maximum order criteria is used for a couple electronic state. And for quantum dynamic calculation, we adopted multi layer multi configuration time dependent hard hard trick using quantum package. So let's go to the result. Here you can see the diabetic a state population of four single basis of the DNA by initially in each case, you can see by initial photo excitation of first bright state that you can see in a green line at time zero, all the population is in the first bright state. But during the time, you can see that in all case, the population is transferred to the dark Empire star a state in a timing, it's transferred to the dark and all bias star a state in the cytosine again in an all bias star a state in other name, it's by initial photo excitation of first brightest is the population is transferred to the end bias star a state. And in one, it's a transfer to the read various state. But when we want to study the DNA in a DNA, we just don't have it just single basis, because DNA consists of the two strand that these two strand is around each other. So there are lots of interaction in the DNA. So for example, one of these instructions is the base is taking the two base on top of each other in a single strand. And the other one is a hydrogen bonding that two bases are in front of each other into a strand, for example, adding the timing and running with the cytosine. So if we want to study the excited state behavior of the DNA, we cannot just concentrate on an interest system process, because the interest system process are a process that happened in each single basis separately. But also we should take care of the inter system process. The inter system process are a process that happened between two bases. For example, the charge transfer is charge transfer is a charge migration from one basis to another base is a kind of the inter system process. So we should also take care of the inter system process. And DNA is a kind of the multi conform system. And if you want to study the multi conform system, more or less up to now, they are using the cytonic Hamiltonian that in this Hamiltonian, they just take care of the inter system process. But in some system that the decay constant of the inter system process is more or less equal to the interest system process, we cannot ignore the interest system process. So in my study, we generalize our LBC Hamiltonian to fragment based diabetization to parameterize a linear vibronic coupling Hamiltonian. The idea of this fragment diabetization is that for example, here, our multi conform system contains up to two bases, two chromophones. So we have local excitation on each form of form. And we use a transition from a occupied molecular orbital of one chromophon to the unoccupied molecular orbital of the other form as a charge transfer state. So we use this charge transfer state and local excitation as our reference state of the multi conform system. So this is again our LBC Hamiltonian. This term is a potential term and this time is a coupling term. So the idea is to obtain this rotational matrix. Mathematically speaking, this rotational matrix has this shape. So this S is an overlap matrix between a reference state and an adiabatic state of our multi conform system. When we obtain this rotational matrix, we can obtain the matrix of the energy that the diagonal one is our diabatic energy and the off diagonal one is a constant coupling between the excited state. So in order to obtain this linear coupling, again, we move a bit along each normal list coordinates. So we obtain just this lambda by numerical differentiation. So let's go to the result. Here I want to show the result of the adenine time in baseband one in site was in baseband. So in an adenine time in baseband, in adenine time in baseband by initial photo excitation of first bright state of the timing, we can see in a black line that during the time the population is transferred just to the an opaque star state of the time in not other state. And if we take a look to the isolated basis, you can see that in isolated base again by initial photo excitation of first bright state, the most of the population is transferred to then opaque star. But the difference is that the amount of population which is transferred to the isolated basis is much more than the baseband. The next one is by initial photo excitation of first brightest state of the adenine which is LA. The population about 70% of the population is transferred to the NNPY star state of the adenine. And if we take a look to the isolated basis of adenine again in adenine by initial photo excitation of first bright state LA in a first 50 femtosecond about 90% of the population is transferred to the NNPY star. And again here you can see that the amount of population isolated basis is much more than in a baseband. Then move to the guanine cytosine. In a guanine cytosine by initial photo excitation of first brightest state of the cytosine which is pi pi star, you cannot see any transfer of population to the dark NNPY star state. But here you see the transfer of population to the charged transfer state, which here the charge transfer state in the charge transfer state is guanine is the kind of the donor and the cytosine acceptor. So we have a charge migration from guanine to the cytosine. And if we take a look to the isolated base you can see that in a cytosine in isolated basis cytosine by initial photo excitation of pi pi star the population is transferred to the NNPY star state. And the last one is the initial photo excitation of first brightest state of the guanine which is LA. Again you can see that in a first 50 femtosecond most of the population is transferred just to the charge transfer state here. First of all to LAB but then all the population is was transferred to the charge transfer state but in isolated basis by initial photo excitation of LAA the population is transferred to the Riedberg state. So in conclusion the hydrogen bond decreased the population transfer from the brightest state to the NNPY star state in a base pair in comparison with the single base. And our quantum dynamic calculation shows that inter-system process of pi pi star to the charge transfer state is the main deactivation process for the guanine cytosine base pair but in an added in timing the intransystem process pi pi star to NNPY star state is a main deactivation process for added in timing. And then let's thank my group Fabrizio Roberto, James, Harita and Daniel and my project is a part of the light dynamic project which is funded by Marie Curie, European onion and thanks for your attention.