 Just a quick announcement about the program this morning. There's been a slight adjustment to it. So we're going to move the electronic structure in Africa part of our program until directly after lunch to accommodate kind of a last minute family emergency of one of our speakers, Professor Frank Niece. So we'll have Frank Niece's talk right after the cone prize session. And then the electronic structure in Africa session directly after lunch. And then we'll continue to talk a little bit about GW and Betus Hall-Peter after the electronic structure in Africa session. So that's a slight change to the program to accommodate one of our colleagues. And it also allows us to get all of the science, keep all of the science into today's program. So just wanted to make that announcement. And I think now I will hand it to Stefano to introduce the cone prize winner. Good morning everyone again. It's my privilege to chair this session for the second edition of the Walter Cone Prize for Quantum Mechanical Materials Modeling. The prize has been instituted three years ago by this institution, by the International Center for Theoretical Physics and the Quantum Espresso Foundation. The prize has been awarded biennially to an outstanding young scientist, young means younger than 45, working in a developing country or in an emergent economy. The International Prize Committee is chaired by Shobana Narasimhan and the other members are Nithya Chetty, Berita Coylor, Sandro Scandolo and Jai Jun Yu. I'm very sorry. I'm very sorry. That was the list of the last edition. The Sandro Scandolo has been replaced by Ras Gebauer, my apologies, Rals. The Walter Cone Prize winner this year is Gabriel Merino from the Center of Investigations and Advanced Studies Unidad Merida in Mexico. I will not read the citation who will be read just before the award of the prize. The prize has been generously co-sponsored by Eurotec for the second time this year. Eurotec is a multinational company doing embedded boards and modules, edge computers, high-performance embedded computers and the Internet of Things platform. Thank you, Roberto, for standing with this initiative. I will not say anything about the scientific figure of Walter Cone. Everybody knows him, I think, from what he has done. He's a giant of science of the past century. But I think it is appropriate and Walter would have been glad to be remembered as a man who went through persecution, was a refugee and a social activist, a very active social activist. I think this is particularly important in these times that are gloomy times for my country, for my continent and for our planet. I think Walter cared much about the planet, about humanity. He witnessed the biggest tragedy of the humankind, who was born in the cradle of civilization. It happened one century ago, it may happen again. So let me just sketch two, three highlights of his life as a persecuted child, a refugee and an activist. Walter was born in Vienna in 1923. Just after the annexation of Austria from the Nazi Germany, his family business was confiscated and he was expelled from public school. He enrolled in a Jewish school and it is said that it is there that he discovered his passion and talent for mathematics and physics. Soon after his expulsion, his parent from school, his parent put him on a kinder transport rescue convoy bound for England, who was organized in Europe to save the lives of too few children. Soon after Walter was shipped to England, his parents were deported to Auschwitz and were murdered by the Nazis. It was not the end because in England he was an enemy because he held an Austrian passport who was, in the meantime, transformed into a German passport. So he was shipped to Canada and enclosed in an detention camp as an enemy alien. He passed away three years ago after a long life spent doing science, advocating peace, nuclear disarmament, international cooperation and, lately, the exploitation of green energy. I take the liberty of telling you an anecdote that Walter told me once. I think it is very typical of the personality of the man. He once told me that soon after he was awarded the Nobel Prize, of course he was invited all around the world and in Vienna as well. As I remember, he told me I may be not very accurate in my memory, but he told me that as many Jews he had mixed feelings about his home country. So he went there with his heart in his hands, not knowing exactly what his reaction would have been. In particular, he knew that it was customary of high schools from which Jew kids were expelled to reward former students expelled with an ex-post diploma. He was determined to refuse it. He was very fond of view of the youth, Walter, and he was moved by the welcoming attitude of the pupils of the very same school from which he was expelled. Little by little he reconsidered his determination and he decided that if the diploma were awarded to him, he would accept it. So he was kind of not this mixed feeling. He didn't know exactly how to react, but at the end he decided to give in. He was called by the principal of the school who held in his hand what he feared he would have in his hand. And he was very proud that the diploma he was awarded to him was not a mature diploma, but a non-mature diploma. He was very proud of it. I have been looking for the evidence of this. I tried to get in touch with his family, but I didn't succeed. So this is all I wanted to say. I will gladly give the microphone to Professor Quevedo who will say a few words to the staff of the International Center for Theoretical Physics. Thank you very much, Stefano. It's a very inspiring word. It's a critical time for all of us. Walter is a big example for scientists in general, but also for the community that ICTP has been working with, scientists that have been developing their own career in difficult conditions. So we are very proud to be part of this award. ICTP, he came many times, and I was fortunate to meet him. He came from... we have after 45 meetings, after 45 years of ICTP, but we had a special conference. He was one of the key participants. Actually, he made himself notice in a very Walter Conway. I think we all remember his participation. He was very inspiring and full of commitment to our mission. So we are very proud to be part of this award, and we thank Stefano and everybody else to run it. So I'm also very pleased that the person who has been awarded to this prize is from my home region, which is a neighbor country and from Guatemala. He's from Mexico. So it's very good that he made it and the committee was able to give him the prize. And we are breaking the record today by having two awards ceremonies in less than 24 hours in ICTP. So that's something that's... it has never happened, I'm sure. But I think it's very good that this field is very well represented in our prizes. And so I think this... we can have the ceremony it's a very good event and we're looking forward to the presentations of Gabriel. So I think now we will give back the microphone to Stefano. Thank you. Thank you, Fernando. I think now it is the turn of Shobana Narasimhan, chair of the committee who awarded the prize. Good morning. Good morning. I'll just spend a couple of minutes telling you about Gabriel Marino and his work. He's a theoretical chemist who has used density functional theory as well as generated new theoretical tools to study a wide range of problems in materials chemistry. He's considered to be one of the world's leading designers of novel molecules. He's particularly noted for work that has explored situations in chemistry where conventional bonding paradigms are challenged. Using a combination of insight, deep chemical intuition and impressive technical expertise. His work has, for example, challenged more than a hundred years of conventional wisdom about how carbon bonds. For example, we all think that when you have four-fold carbon, it is tetrahedrally coordinated and he's been the first to show that you can have planar four-fold coordinated carbon and also you can have hypercoordinated carbon. Another thing that he has done is he has developed new tools to extend our ideas of concepts in chemistry such as structure, coordination, the chemical bond and aromaticity. For example, another piece of work that he's very well known for is that you can study aromaticity by looking at how systems respond to an externally applied magnetic field and use that response to classify the aromaticity. And this also allows one to extend the concept of aromaticity from organic materials to inorganic materials. He has also worked on many other kinds of problems such as reaction mechanisms and he has come up with interesting flexural molecules which can be looked upon as molecular motors. I think it's very important to note that all of this work has been done in Mexico which is a developing country and it has been done with fairly limited resources and he has built up a strong group there. So this is of course an important part of the reason why he was chosen for this prize. So the committee was very happy to select him for the Walter Cohn Prize. So I now read the citation. The Walter Cohn Prize for 2018 has been awarded to Professor Gabriel Marino for his pioneering work on predicting and understanding novel systems that violate standard chemical paradigms and for generalizing and broadening the scope of concepts such as aromaticity, coordination and the chemical bond. Thank you very much. It's an honor to be here for many reasons and it's an honor to receive this prize not just because it's my it's a recognition for my work and also for the work of my the work of my group, it's also a recognition for the theoretical chemistry in Mexico. So thank you, thank you very much. So today I will speak about our work in the last 10 years and we are focusing on classical carbon and bond molecules. First, this is my group in Mexico, okay. There are several people that are doing PhD and also mastered in science and there are too many people that are passed by this group in the last 10 years. This work it's done by many, many people in collaboration more than 100 people that in the last time I so these are the most important collaborators around the world. So and for example, there are some people from Mexico, Alberto Vela that was my advisor people from Germany, from India from Europe. So many people around the world. You know well that there are two basic rules to build any organic molecules, okay. The first one is was suggested many years ago by Kekeule and it say that when carbon the maximum coordination number of carbon it's four, okay. So it's possible to find molecules with three coordinate carbon atoms with the coordinate carbon atoms but the maximum coordination is that and using this rule he was able to explain the physical and chemical properties of many, many organic molecules at that time. But and the second rule is that when these four ligands are linked to carbon they will distribute it in one tetrahedron. So there are right now more than 30 million of molecules that follow these two basic rules and the first exceptions of these rules appears in the middle of the last century and this is these very small molecules it's only five hydrogens atoms actually it's a cation, okay. So this molecule is very important because actually it's the product of the protonation of methane and it's when a molecule with these molecules it's in one very acid medium it's possible to obtain that, okay. Also it's because the product of the protonation when the molecules methane it's in the universe and it's also a way to know how many gears has one galaxy or something like that in astrochemistry, okay. So but the most important at that moment is that what's impossible to explain the chemical bond and also the structure of this very small molecule, okay. There are several important things for instance if you compare this is the infrared spectrum from these molecules in the region that of the carbon hydrangea stretching and for this couple of molecules you have only 300 lines, okay, 300 so the spectrum is quite well defined and it's possible to extract information structural information from these two, okay. So but in this case there are more than 1,000 lines and it's not possible to say what is the structure of the molecule so because the molecule is fluxional okay so it means that actually the molecule doesn't have a structure, okay. After that appears many molecules with a pentacordinate carbon atom so here there are some examples with hexacordinate carbon atom and all of them are synthesized, okay. For instance when carbon is surrounded by lithium, boron, ruthenium, rhodium, not gold it's possible to have such type of molecules when carbon is surrounded by six ligands it's hexacordinate carbon atom, okay. And two years ago I guess two years ago appears these molecules are very interesting because first is crystallized second it's because here is a carbon surrounded by six ligands but all of them are carbon so it's a carbon cation with a carbon, with a hexacordinate carbon atom so it's a quite interesting molecules and actually was crystallized this is the most important thing because was the first hexacordinate molecules crystallized. But there is also possible to find such type of coordination in biological systems here we have one active site, one protein when the carbon is surrounded by six iron atoms okay and all of them and carbon is quite important to maintain the structure here so a carbon in such situation are also important for some proteins perhaps one of the most important carbon cations is this one is a norbanil cation it's a pentacordinate it's a molecule contain a pentacordinate carbon atom this one you can see that there are two bonds to the hydrogen atoms one with the other carbon and here there is a strange bonds between this carbon and this two okay it's a pentacordinate carbon atom so and actually this structure was suggested in order to explain the properties and also the reactivity of this type of molecules this one are carbon skeleton is in several natural products okay and was suggested by Beinstein and Trifant in 1945 okay so but it was not accepted immediately so this was a non-classical view with a pentacordinate carbon atom but Hebert Brown's Nobel Prize in chemistry say that this is not possible actually that actually there are very fast change between classical two classical carbon atoms so this is a tetracordinate carbon atom and actually there's an equilibrium and this is the way that Hebert Brown explained that this is strange because actually Hebert Brown was one of the most active chemists in in boron chemistry actually and he suggests or he supports his theory basically multi-center bonding multi-center bonding is the way to explain such type of pentacordinate carbon atoms so but right now there are too many evidence and actually for this reason Joshua won the Nobel Prize because they explained using NMR another spectroscopy how it's possible to have this pentacordinate carbon atom in solution in crystal and also in the gas phase so but this molecule still has some interesting things this was the crystal structure of this molecule was published in science six years ago actually and you can see that even at 120 Kelvin the molecule is still moving a lot okay but when we reduce the temperature until 40 Kelvin it's possible to have to check that this carbon this particular carbon atom is pentacordinated so five years ago appears this very nice paper in Angewante and actually they only tried to obtain the infrared spectrum from this molecule okay but they use a new technique use infrared a new infrared technique and actually they obtained that also at the same time okay so there is an improvisation between this molecule and this one but nobody understand what is the way the mechanism to transform this structure to this one this is a classical carbon system so you don't have pentacordinate carbon atom so the idea is try to explain how it's possible to move from here to here so in collaboration with Paul Slayer we try to explain how it's possible to move from here to here and we found using molecular dynamics that it's a very complicated mechanism actually at low temperatures this molecule is not moving so there is an interchange of the multi-center bonding but when we increase the temperature everything changes so first the molecules it's open and later on we recover the five-member rings okay so actually these molecular dynamics simulations it's a Boron-Penheimer molecular simulations everything it's here so there is one transition state that this is the most important transition state it's around 30 kilocal per mole a little more so this is the reason why these molecules it's kinetically stable and to move from here to here there are a lot of steps that we need to do so but the most important is that the chemistry the reactivity and also the stability of this molecule it's quite complicated so we apply exactly the same behavior the same technique sorry for this strange molecule this is also a carbocation here we also have a pentacornate-caron atom and people say that it's possible to have too many arrangements so actually the molecules it's interesting because in NMR we have only one signal and one signal of hydrogens it means that all the carbon and hydrogens are moving at the same time and the general view is that all of them have a similar environment and the problem is that nobody understands these mechanisms so we use also molecular dynamics for that and we obtained that actually the molecule is moving all the time so the six-member rings are from the molecules and this is the way to explain that the transition state related with that it's this one the first transition state is only the rotation of these six-member rings and this rotation expands only 0.8 kcal per mole it's nothing actually and the second one it's this one so in this case the carbon-hydrogen this fragment is moving from here to here and this is the way that the carbon-hydrogen fragments have exactly the same environment so but what about the second paradigm of organic chemistry so it's possible to stabilize planar tetra-coordinated carbon atoms so in this case we have in this case a Royal Hoffman suggests many years ago the way to stabilize planar tetra-coordinated carbon atoms and actually it's a very nice paper actually a two-paper page and the half of this page this paper is this molecular diagram so and using this simple molecular diagram he is able to explain that so here we have the atomic orbitals of carbon so S and P and here we have the molecular orbital of this hypothetical fragment H4 and when we mix this orbital with this one by symmetry we build this fourth occupied molecular orbital so in this case these three molecular orbitals are related with the bonding between the carbon and the hydrogen and here there are one lump and actually this is a big difference with the with the carbon-hydrogen with the classical methane molecules so here in this case this lump pair is the reason why the molecule is so unstable and Royal Hoffman suggests that in order to stabilize this molecule it's mandatory to remove this lump pair so one way is simply to remove that and to create the the cation and the other is to introduce that the magnetic system in order to remove this one and the last one is to change the hydrogen by metal systems in this way this lump pair can be removed and actually the first system that was synthesized was this one this is the the system the first system that was crystallized was published by Albert Cotton but actually he was more interesting about the bondings between these two metal atoms these two are vanadium atoms and this was one of the first molecules containing a quadruple bond between a couple of vanadium atoms but if you check this carbon atom and this one has four ligands around and all of them are tetra-coordinated carbon atoms see this molecule is the first molecule containing a couple of planar tetra-coordinated atoms right now there are several examples synthesized or detected in the gas phase and also a lot that are predicted on computer and there is more cluster for instance when carbon is run by silicon, gallium or aluminum it's possible to have that when carbon is this for instance is a typical three-center three-member range when a couple of hydrogens are substituted by lithium it's possible to have this molecule that has a planar tetra-coordinated carbon atom these molecules it's also quite interesting because at the same time you have a planar tetra-coordinated carbon atom this one but also you have a pentacordinated carbon atom and there are several molecules that are used in catalysis that also contain this environment okay okay so this was the first work in our group related to that this is a very simple molecules containing a planar tetra-coordinated carbon atom but when carbon is surrounded by four carbon atoms actually we test DFT but we also test a copper cluster and mp2 in order to know that this is not an artifact of this level of theory and we found that in all levels these molecules it's a local minimum so this is the way to understand what's happening this is a sphere compound it exists actually when we remove these four protons we form this tetra-ion but in order to rotate we locate one lone pair at this position and now we have two possibilities to remove these two electrons so we can remove from here to here and the computations say that actually that the best way to remove this one is this position okay so in this way we have this planar c5 to minus okay so when this fragment is surrounded by metal atoms so the fragment is still stable okay so we try to remove this charge in order to put a lithium sodium potassium and also calymetals that are brilliant to calcium and in all the case the structure is local minimum and actually we can put two around and also the system is local minimum actually one of the most important figures in this couple of papers is this one so the barrier to transform these fragments to classical ones it's very few it's only less than 20 kilojoules per mole and the energy difference between this couple of local minimum is around 180 kilojoules per mole so it means that this molecule is not even kinetically stable but when we include metal around so first the barrier increase it's around 60 kilojoules per mole and the energy difference between this couple of isomers is now less than 8 kilojoules per mole so the metals around this fragment stabilize this strange structures and in collaboration with Royal Hoffman we start to study several of these structures in the crystal phase so here we have some examples with Berylone and Sink it's actually the same topology so in this case there is a B-dimensional change in the case of lithium we have a different topology in this case the CIF 5 to minus fragment is surrounded by four lithium atoms and with platinum we also have different topology in this case the platinum is linked to a couple of carbon fragments and the platinum is linked to four carbon fragments in this particular case we have hydrocarbons contained in such type of fragments so here we have a 5-member ring 6-member ring etc and all of them are local minimum again these molecules are stabilized because all this fragment is totally delocalized without saturation in this fragment and we create this bond we have exactly the same situation and also in this case it's a local minimum so the problem here is that for some examples this is quite okay because the structures are quite strange but they are not the global minimum it means that in the gas phase it's almost impossible to detect such type of molecules so people try to detect these molecules not only to have this in computer so for this reason we move or we try to find what is the global minimum of our system containing such type of structure but to be the global minimum so in order to explore the potential energy surfaces of such type of fragments of molecules or even for crystals it's necessary to do genetic algorithms to do another type of heuristic that explore all the potential energy surface for instance for the case of C6H6 we know very well that the multistable structure is this one it's been seen, it's here but there are around 240 different structures with the same with the same stoichiometry so it means that all of them has the possibility to be stable but the multistable and actually it's a very deep global minimum, it's this one so the idea is to explore all the potential energy surfaces and try to find molecules containing one type of structure and actually this was our first work to make that so here we apply one genetic algorithms in order to find one molecule containing a planar tetrachornate carbon atom, these are very simple molecules we explore all the possibilities so when the system is a neutral one the carbon is 3-coordinated but when it's a cation the carbon is tetrachordinated it's surrounded by these 4 boron atoms ok so from here to the ends all of the systems that I will show you are global minimum so it means that they can detect it in the gas phase so if we surround carbon by aluminum containing one lithium this fragment is also a global minimum it's a diion ion and in order to remove one of the charge we put one lithium atom these are an ion all these molecules or these clusters are global minimum and when carbon is surrounded by 4 aluminum or 4 gallium atoms they are tetrachornate carbon atoms but when they are surrounded by indian and thallium the carbon is pentacornate so it's not only to select exactly the same elements for the same group it's also that each of them will have different topologies so if planar tetrachornate carbon atoms are interesting now think about planar pentacornate carbon atoms the first example was suggested by a polish liar and actually was detected by a mass spectrometry by the professor Senk here the carbon is surrounded by 4 aluminum atoms and actually it's a cation so the interesting thing here is that all the molecules that are global minimum at least for now right now there are some exceptions has 18 balance electron around so using this rule we can predict many other molecules for instance if we remove one of the aluminum for the previous one and now we substitute by beryllium we have exactly the same structure we have a pentacornate in one plane so in this case we can think that we only substitute one aluminum beryllium and we optimize that now we explore all the potential energy surface and we found that this is the global minimum structure so when we substitute by magnesium that could it's quite similar but we don't obtain that we obtain something like that that the carbon is tetracordinate so in this case we spent a coordinate because the size atom of the beryllium is very small one and this is the way that beryllium interact with the carbon atom so using this 18 balance rule we try to suggest a planar exa-coordinated carbon atom but nobody found actually our first attempt we have 5 beryllium atoms of one aluminum but the maximum coordination of carbon at this moment for a planar system is 5 so it's impossible to go to 6 and here we have another examples of global minimum containing a planar pentacornate carbon atoms here we have 5 beryllium atoms this is tetranion when we substitute we surround these by lithium atoms we obtain a planar start like molecules in this case is a cation this is a trianion and all of them are global minimum okay we also use these 18 balance rules to try to predict the first organometallic compounds with such properties because we know that in the case of planar tetracornate carbon atoms these fragments stabilize these strange carbon molecules and in this case this is a global minimum so in this case we have 4 aluminum atoms okay around that and these transition metal atoms in this case is circunion on a half new it's possible to interact with the carbon and have a planar pentacornate carbon molecule all this work is reviewing this natural reviews paper and there are some attempts to create planar hexacornate carbon atoms so the first one was published in science by Paul Slayer and in this case the carbon is surrounded by 5, sorry by 6 boron atoms is a di anion but it's not a global minimum and actually using this model in collaboration with Paul Slayer we suggest several wheels to create atoms in the middle so in this case carbon is able to stabilize the anion with an hexacornate and also epacornate carbon atoms but in both cases there are just local minimum when we try to put carbon in the middle of one 8 member ring so this is too small and actually it's not possible to find the local minimum but with silicon it's possible so we found a rule that when we increase the ring size so it's mandatory to remove one of the one of the electrons so in this way it's possible to find that but again this is not a global minimum so we publish before to start to use or to generate genetic algorithms and another methodology to explore the potential surface problem so the only detected structure is this one this is the global minimum and the other one is more than 30 kilocal per mole so this will be never detected but it's a local minimum so in the gas phases cluster chemistry the only system that will be detected is the global minimum and perhaps molecules around one two or three kilocal per mole okay nevertheless using this knowledge it was possible to predict the first deca-coordinated planar atom okay in this case it's not a main element it's a nobium, a tantalum and it was detected in the gas phase by Lai-Sheng Wang and Alexander Valdiref and again this is the maximum coordination for one atom for a planar structure okay so it means that for boron cluster so the hyper-coordination it's quite natural here there are the global minimum structure for several, for small boron clusters so from 3 to 15 okay there are some cations and ions and neural systems and for instance for 8 boron atoms this is the global minimum here we have an octa-coordinated boron atom and for boron 9 minus we have an octa-coordinated boron atom okay so in this case this molecule was suggested in 2010 so we have the opportunity to work with Alexander Valdiref and during one meeting in our lab so we discussed how it's possible to understand the stability of such type of molecules they found experimentally that this is the most stable structure so theoretical and experimentally and it's interesting because you have a pentagon in the middle of one ring of with 13 boron atoms okay and one of them, one of the boron atom it's in the middle okay there are a second isomers but it's around 2 kilocalpere and actually both of them were detected experimentally the other are very high in energy and they are not contribute to the spectrum so but actually we found that there are another structure that it's very close in energy so this was suggested by error actually one of my postdoc so because it's quite similar this one okay here we have three bonds here we have only two bonds okay here we have triangles here we have squares okay it's quite similar and the energy difference between these two structure is just 1.5 kilocal per mole it's nothing actually and when and this is not a local minimum actually this is a transition state and this transition state related with the rotation of this inner fragment and because the barrier is quite small less than 1 kilocal per mole so it means that the fragment is rotating all the time okay so it's independently on the temperature so when you have when you detect this cluster actually the molecule is rotated okay so we were thinking that this were the only example with that but one year later we discovered that also boron 13 plus that is one magical number in boron clusters it's also rotating so here in this case we have a triangle in the middle and also it's also rotating okay so it means that many boron clusters have this fluxional behavior okay in some cases these are very small in other are a little higher so but it's possible to find that so it depends also of the structure if you have the correct size of the surrounded ring but in principle this molecular behavior it's possible because all the connection between this inner fragment and the external ring is using multi-center bonding it's not a typical to center to electron bonds you can share 3, 4, 5 electrons between several atoms okay so here also have we have boron 11 minus in this case we have a dimer here in the middle and in this case it's rotating so it means that also it's possible to find this fluxional behavior here okay so here there are several of these structures so for instance in this case the barrier is quite high it means that the molecules are not fluxional but in this case we have boron 11 for cation, neutral and anions all of them are fluxional and so we check all these structures these are the global minimum until boron 20 and two years ago appears this experimental paper using infrared spectroscopy for boron 13 plus and they prove that this structure is fluxional actually so it means that it's not only one crazy idea about theoretical chemistry so this is the same ideas were applied for this cage structure this boron cage boron 40 okay so this molecule this cluster is quite interesting because actually the first cage structure and people say that is the analog of the c60 the fuller ring but using boron but in this case we don't have 6 and 5 member rings we have 7 member rings 3 member rings 4 member rings and this is the global minimum for such stoichiometry we apply exactly the same this is a molecular dynamic simulation and you can see that all the boron atoms are moving so we classify these molecules like a nano bubble because actually all the boron atoms are on the surfaces and the surface of that okay so more recently we found another interesting molecules for instance this is in collaboration with some with a group in China here we found the first elix boron system so this is the global minimum the red atoms are boron but they are supported by one small berylene cluster okay it's here okay but there are another structure that is very close in energy is 0.5 kilocal per mole and we have here 3 layers system okay and my colleagues found that this is also a vankel motor actually but in this case they are independently okay there are 3 fragments that are rotation at the same time okay so the functionality it's also explained using this multi-center bonding because without that it's impossible we have one to center 2 electron bonds the structure is not rotated it's just because you have such type of electron distribution is because the molecule is rotating okay right now we are trying to find nanotubes with boron okay so in this case we found that when the cluster boron cluster is surrounded by lithiums in order to change the charge of this system it's possible to find different topologies for instance this is the the most stable structure for lithium boron 12 okay so actually it's quite similar to the naked boron cluster okay when we introduce another lithium atoms it changes drastically this is the global minimum so here you have a small tube and when we introduce another one now you have a cage so it means that the lithium changes drastically the structure and it's this is strange because actually lithium is considered just one cation that will not change the structure but it can place a different role to stabilize such type of structure here we have our first attempt to build a tube okay so this is boron 14 sorry 24 with a couple of lithium atoms okay and this is the global minimum and we have a three layers system and this is the first global minimum containing such type of topology okay using these techniques these genetic algorithms and also another heuristic to explore the potential energy surface it's possible to use for many other many other problems so for instance we apply also for micro-solvation okay so because in this case we don't have atoms we have molecular fragments so one molecular fragment could be water and using that we can the global minimum for such type of system so and we use this in order to understand the micro-solvation on small cations and anions and also to understand the dissociation of acid for instance okay and here we have another topic that we are checking so we are so interesting in aromaticity we are interesting carbocations and micro-solvation, noble gas chemistry, organometallic compounds mainly some mechanics reactions and also non-covalent interaction in order to understand how it's possible the interaction between a couple of molecules okay so let me show you where is Merida actually Merida is here it's quite close to Cancun maybe you recognize Cancun no Merida okay Cancun is here Merida is here and we are in the Magian area so we have around many beautiful places so here is one of the most important parameters here it's Chenitza but we have also cenotes and around we have a lot of beautiful ecological system like this one so it's a very beautiful place for visiting and thank you very much for your attention thank you for the beautiful presentation we have time for a few questions please you didn't say a single word about the electronic structural methods you are adopting in all of those calculations we would like to know more of course yeah so in all the cases in all the cases we explored the potential energy surfaces using DFT but we know that in some cases DFT is not enough to reproduce the numbers we use PV0 we use the Minnesota functionals but all of them we re-optimize and also we check the energy for small cluster using coupled cluster because the idea is to really to find the global minimum so the other important thing is that when we have one experiment it's possible to compare the photoelectron spectrum so we compute also the photoelectron spectrum and this is quite our computed spectrum is close to the experimental one we are sure that the global minimum is that that we found but this is our main methodology the first optimization is with DFT PV0 and the second one is using coupled cluster in order to be sure that everything is okay for that we use and and generally we use what is the name of that it's a vertical attachment energy and for that we use the theory what is the name of that sorry I don't remember but we use another level of theory for that so it's not using DFT so I have a question so first of all what do you think about the dynamics what was the temperature in this molecular dynamics runs because we want to show this in a short time we use a temperature around 300 Kelvin, 600 Kelvin in order to check this rotation later on we compute the barriers in order to be sure that the barriers are smaller okay and do you think that it's possible to consider an irrelevant quantum effect like we run open-hybrid molecular dynamics but it's mandatory to use another type of system we are sure about that because we also compute the barriers in static computations and we found exactly the same numbers my question is can you think about integral Monte Carlo calculation of the system for example there are some groups that make that does this change the landscape the results are the same because actually the second isomers are far away and it's not possible to see the isomerization we only see the rotation of the inner ring okay so thank you very much for your good talk I have a question so if the spin states of the system changes during the molecular dynamics how do you handle that I guess you fix it like say what if during the simulation in reality this spin state changes how do you handle that I don't understand the question but in principle we are checking all the so we fix in the middle one view and we are checking that all the system is rotating around and what I mean is so you start with the singlet if when you do the simulation maybe it goes to a different spin state so the high spin state are quite high in energy more than 50 kcal per mole so I guess at least for molecular dynamics it's not possible to access to such type of structure sorry a one kill engine rotates one way your thing rotates half the time one way and half the time the other way actually it's rotating in both sides because the barriers are exactly the same there are one group in gcla that apply one polarized light in order to change one of the barriers and in this way now the motor is rotating only one side carbon is observed to be 6-fold coordinated in the liquid state as well their electronic structure is totally different it's metallic actually liquid silicon is metallic and the coordination is kind of cubic is there any relation between the fancy coordination states you observe in molecules with what would be observed in the liquid state really I don't know so but I know that when the conditions change drastically it's possible to obtain such type of coordination so for instance when people start to press the graphene or other such type of crystal of carbon system it's possible to obtain high coordination numbers in liquid I don't know but in principle I think it's possible thank you very much