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4th Edition of

Chemistry World Conference

June 17-19, 2024 | Paris, France

Chemistry 2023

Orchidea Maria Lecian

Speaker at Chemistry World Conference 2023 - Orchidea Maria Lecian
Sapienza University of Rome, Italy
Title : A new lemma of the optical equivalence theorem: Applications in theoretical chemistry and new challenges


The Optical Equivalence Theorem demonstrates the equivalence between the expectation value of an operator in the opportune Hilbert space  and the expectation value of the pertinent  functional representation in the phase space formulation with respect to a suitable distribution; for the purposes of this demonstration, a phase space reprenstation is chosen, which does not involve the Number operator. The Optical Equivalence Principle allows one to construct a sequence of the density operator. A new lemma of the Optical Equivalence Theorem is demonstrated, after which there is associated with the quasi-probability distribution and improved functional reprentation as far as the allowed expansion order is concerned; the construction is apt to codify almost-inifinite-momentum states. A compact-support control weighting function is introduced, to display the action of operators of high-intensity fields, whose states are determined. Applications in Theoretical chamistry are provided with.  Applications are explained within molecular dynamics trajectories: the atomic coordinates at specific times are framed in the phase space, where the new improved reprentation of the quasi-probability distribution is used to improve the long-time-limit error calculation in  the quantum fluctuations, quantum jumps (also in lasing), comparison of chemical shift with MNR spectroscopy for control of composition; Markovv modelisation: the long-timescale dynamics of molecular systems is analysed as consisting of probabilistic jumps between est of states, which are now newly issued as those which are the pertinent states of the new improved functional representation:
 quantum fluctuation, transition to lasing, carrier energy states, comparison with Monte-Carlo simulation; mocular chemistry: protein stability and folding kinetics, coordinate shift with determination of transition states, transmission probability, definition of entropic reaction coordinates; laser molecule activation; transition state spectroscopy: potential energy surfaces are newly established within the new representation of the phase space; molecular activation: the process of the molecular activation is framed within the new representation of the states within the new representation of the phase space obtained after the new improved representation of the probablity- distribution sequence. New challenges are envisaged.


Prof. Orchidea Maria Lecian graduated in Theoretical Physics at Sapienza University of Rome and ICRA- International Center for Relativistic Astrophysics in 2005 and completed her International Relativistic Astrophysics Phd at Sapienza University and ICRA. She was post-doctoral Fellow at IHES (Bures-sur-Yvette, France), AEI-MPI (Potsdam-Golm, Germany) and Sapienza University of Rome. She has taken part in intensive research programmes at AEI-MPI (Potsdam-Golm, Germany) and The Fields Institute for Research in Mathematical Sciences (Toronto, Canada). She has been researcher for  SAIA- NS'P (The National Scholarship Programme of the Slovak Republic- National Stipendium Program) as Research grantee and appointed Erasmus Lecturer at Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics, Department of Theoretical Physics and Physics Education- KTFDF.

She has been Assistant Professor at Sapienza University of Rome and is Professor at Sapienza University of Rome. She is wasVisiting Professor at Kursk State University, Chair of Algebra, Geometry and Didactics of Mathematics Theory within the Programme Education in Russia for Foreign Nationals of the Ministry of Science and Higher Education of the Russian Federation in 2022-2023. She has contributed in national conferences and international conferences. She is member of several Research Consortia. She is author of research papers, conference papers, review papers, invited papers and two books. She is reviewer and editorial-board member of several Journals.