Faculty Information
Aniruddha Chakraborty
Office:
Personal Information
Professional Experience
Associate Professor: School of Basic Sciences, Indian Institute of Technology Mandi, Himachal Pradesh, India, 2015 .
Assistant Professor: School of Basic Sciences, Indian Institute of Technology Mandi, Himachal Pradesh, India, 201015.
Research Associate: Institute of Theoretical Sciences & Department of Chemistry, University of Oregon, USA, 200509. Supervisor: Prof. M. E. Kellman.
Research Associate: Condensed Matter Theory Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, India, 200405. Supervisor: Prof. K. L. Sebastian.
Educational Background
Ph.D.: Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore, India, 19972004. Thesis Advisor: Prof. K. L. Sebastian.
M.Sc. (Chemistry): Specialization in Physical Chemistry, University of Calcutta, Kolkata, West Bengal, India, 199597.
B.Sc. (Chemistry Honours): Vivekananda College, Kolkata, West Bengal, India, 199295.
Broad Area
Theoretical & Computational Chemical Physics
Specific Areas
 Dynamics of Barrierless Reactions.
The standard model for irreversible chemical reactions in solution would be a particle executing onedimensional random walk on a harmonic potential, in presence of a point sink, located at an arbitrary position. An exact analytical time domain solution to this model was proposed by us. This has been an unsolved problem for long time and is of considerable importance as a model for chemical reaction in solution. We are able to solve problems beyond point sink model as well.
The standard model for reversible chemical reactions in solution would be a particle executing one dimensional random walk on two potential wells in presence of coupling between them. Exact Laplace domain solution of this model for pointlike coupling between two potentials was proposed by us. This is an interesting & very important work in this field. Very recently we have proposed an exact analytical time domain solution of this same model, which was so far considered to be analytically intractable.
 Multistate Problems in Quantum Mechanics.
Nonadiabatic transition due to potential curve crossing is one of the most important mechanisms to effectively induce electronic transitions in collisions. We consider two curves crossing each other & there is a pointlike coupling between two curves, which causes transition from one curve to another. Exact solution of this model was proposed by us! This is an interesting & important work in this field. Our method of solution is used extensively to solve few related problems.
 Effective Spectroscopic Hamiltonian.
A reliable potential energy surface is required for studying the dynamics of a molecule in a particular electronic state. For polyatomic molecules, a global potential energy surface is out of reach of current computational capabilities. So one possible way to make progress is to use analytical functions with several parameters to fit the experimental data for constructing an effective Hamiltonian. One can use these effective Hamiltonians to extract new information about dynamics from information encoded in experimental spectra and to use these information to understand internal molecular energy flow and reaction dynamics. Even when the potential energy surface is available, effective Hamiltonians are constructed from the exact Hamiltonian in order to simplify the subsequent analysis. We have recently developed the first generalized polyadbreaking effective spectroscopic Hamiltonian for understanding bond dissociation process.
 Buckled NanoRod: A Two State System.
Twostate nanomechanical systems (mechanical equivalent of 'bit') are very interesting examples for the possibility of observing quantum effects in them. The compression of a nanorod would cause it to buckle. There are now two possible states, and the system is interesting, as a potential nanosized device. We have developed quantum mechanical methods for the calculation of the rate of transitions between the two states, due to thermal fluctuations and tunnelling. Our method goes beyond the standard method (Transition State Theory). In future our plan is to analyze the same problem in detail using dynamical transition state theory.
 Proton Tunneling through aromatic/antiaromatic ring  Two State Problem.
Proton tunnelling through ring compound with pi electrons is an interesting problem to study. It may be helpful in understanding electrophilic substitution reaction in solution as well as proton tunnelling in biosystems. Here we will consider two types of planer ring compounds, one is aromatic and the other is antiaromatic. Our aim is to study the effect of electron transfer from the ring compound to proton. So we will assume one dimensional model for motion of proton along a line perpendicular to the plane of benzene ring as well as through the middle of the benzene ring and construct a potential energy curve for the corresponding motion. We will repeat the same procedure for motion of neutral Hatom through positively charges benzene ring. We will use computational chemistry software for computation.
 Understanding Mechanism of Opening and Closing of Loop of a Long Polymer Chain.
Understanding the kinetics of loop formation of long chain polymer molecules has been an interesting research field both, to experimentalists and theoreticians. Loop formation is believed to be an initial step in understanding several protein events. The theories of loop formation dynamics are in general approximate. The looping dynamics of a single polymer chain having reactive endgroups have been modelled by simplest possible option. In our model, dynamics of endto end distance is mathematically represented by an equation for a random walking under harmonic potential. Looping process is ensured by adding a sink of arbitrary strength in that equation. We have also incorporated the effect of all other chemical reactions involving either one or both of the endgroup on rate of endtoend loop formation  to the best of our knowledge this is the first time this has been done in any analytical model. An important future direction of this research is to understand the dynamics of contact formation between different parts of a long chain molecule. We will perform Brownian dynamics simulation studies of looping of a single polymer chains to see how ' shape of the sink function' decides the looping dynamics.
CY242 : Introduction to Molecular Spectroscopy.
IC101 : Fundamentals of Chemistry.
IC130 : Engineering Chemistry.
IC101(P) : Laboratory Chemistry.
CY 704: Introduction to Theoretical Chemistry.
CY245: Nanoscience  Understanding Small Systems.
CY247 : Molecular Thermodynamics.
PH214 : The Physics Behind Computers.
CY342: Food Chemistry.
CY521: Mathematics for Chemists.
CY551: Computational Chemistry.
CY513: Reaction Dynamics, Kinetics & Catalysis.
CY512: Advanced Quantum Chemistry.
CY511: Group Theory & Spectroscopy.
'Teaching Honour Roll' award at the Institute's Teacher's Day Celebration, 2018 (IIT Mandi, Himachal Pradesh, India).
'Foundation day' award for excellence in Research at IIT Mandi, Himachal Pradesh, India 2016.
Invited by the Chair, Teaching & Learning Committee of IIT Mandi for giving a short speech at the Institute's Teacher's Day Celebration, 2016.
'Foundation day' award for excellence in Teaching at IIT Mandi, Himachal Pradesh, India 2013.
'Foundation day' award for excellence in Research & Teaching at IIT Mandi, Himachal Pradesh, India 2011.
Selected for IUPAC Young Chemist Award (Progm. B), by the Royal Society of Chemistry, UK, 2009.
Selected for the Carl Strom fellowship for attending GordonKenan Graduate Research Seminar on Molecular Energy Transfer in Buellton, California, USA, January 89, 2005.
Senior Research Fellowship, by the Council of Scientific and Industrial Research, Government of India, (2000  03).
Junior Research Fellowshipand eligibility for lectureship, by the Council of Scientific and Industrial Research, Government of India (1997  99).
Graduate Aptitude Test in Engineering (GATE  1997), with percentile score: 99.24 & All India Rank  12.
National Scholarship by Department of Education, Ministry of Human Resource Development, Government of India, on the basis of B. Sc. Exam. Result (1995).
National Scholarship by Department of Education, Government of West Bengal, India, on the basis of Higher Secondary Exam. Result (1992).
Aniruddha Chakraborty
Theoretical Chemical Physics
Computational Chemical Physics
We have been interested in understanding chemical phenomena theoretically. Our research interests have been very diverse and include quantum chemical calculations, chemical reaction dynamics, electron transfer reactions, dynamics of polymers, dynamics of nanodevices, chaos in molecular systems and biophysics.
 Propagator calculations for time dependent Dirac delta potentials and corresponding two state models, S. Mudra* & A. Chakraborty, Phys. Lett. A, 2021, 418,127725.
 Rattling motion of proton through five membered aromatic ring systems. S. Chamoli* & A. Chakraborty, Comput. Theor. Chem., 2020, 1183, 112825.
 Understanding the reversible looping kinetics of a long chain polymer molecule in solution with Dirac Delta coupling. M. Ganguly* & A. Chakraborty, Physica A, 2019, 536, 122509.
 Buckled Nanorod  Dynamics of a two state system treated with an exact Hamiltonian. J. Dehning* & A. Chakraborty, Chem. Phys. Lett., 2015, 636, 193.
 Barrierless electronic relaxation in solution: An analytically solvable model. A. Chakraborty*, J. Chem. Phys., 2013, 139, 094101.
 2022

 Reactiondiffusion dynamics in presence of two competing sink terms: Beyond OsterNishijima Model in barrierless reaction, C. Samanta* & A. Chakraborty, Physica A, 2022, 594, 127061.
 2021

 Propagator calculations for time dependent Dirac delta potentials and corresponding two state models, S. Mudra* & A. Chakraborty, Phys. Lett. A, 2021, 418, 127725.
 Exact analytical solution of time independent Schrodinger equation for a system consist of two flat potentials coupled by a rectangular potential, P. Mondal* & A. Chakraborty, Mol. Phys., 2021, 119, e1968055.
 Exact results for the Schrödinger equation with moving localized potential, C. Samanta* & A. Chakraborty, Phys. Lett. A, 2021,408, 127485.
 Reactiondiffusion dynamics in an attractive stepwiselinear potential energy curve under the gaussian sink action, C. Samanta* & A. Chakraborty, Eur. Phys. J. Plus, 2021, 136, 1.
 Diffusionreaction approach to electronic relaxation in solution: Exact solution of Smoluchowski equation for parabolic potential in presence of a rectangular sink, P. Mondal* & A. Chakraborty, Chem. Phys., 2021, 548, 111206.
 Transition time estimation for δfunction coupling in two state problem: An analytically solvable model, M. Vashistha, C. Samanta* & A. Chakraborty, Chem. Phys. Lett., 2021, 770, 138436.
 Diffusion on a flat potential with a rectangular sink of arbitrary width: Exact analytical solution in Laplace domain, P. Mondal* & A. Chakraborty, Physica A, 2021, 567, 125707.
 Opening of a weak link of a closed looped polymer immersed in solution. Analytical modelling using a Dirac delta function sink, M. Ganguly* & A. Chakraborty, Phys. Scr., 2021, 95, 015003.
 Diffusion dynamics in the presence of two competing sinks: Analytical solution for OsterNishijima's model, R. Saravanan* & A. Chakraborty, Physica A, 2021, 563, 125317.
 2020

 The twostate reversible kinetics of a long polymer molecule in solution with a delocalized coupling term. An exact analytical model. M. Ganguly* & A. Chakraborty, Phys. Scr., 2020, 95, 115006.
 Some exact timedomain results related to reversible reactiondiffusion systems. R. Saravanan* and A. Chakraborty, Chem. Phys., 2020, 539, 110955.
 Reactiondiffusion approach to electronic relaxation in solution: Simple derivation for delta function sink models. S. Mudra* and A. Chakraborty, Chem. Phys. Lett., 2020, 751, 137531.
 Rattling motion of proton through five membered aromatic ring systems. S. Chamoli* & A. Chakraborty, Comput. Theor. Chem., 2020, 1183, 112825.
 Analytical Solution of diffusion probability for a flat potential with a localized sink H. Chhabra* S. Mudra & A. Chakraborty, Physica A, 2020, 555, 124573.
 Looping of a long chain polymer in solution: Simple derivation for exact solution for a delta function sink. M. Ganguly* & A. Chakraborty, Chem. Phys. Lett., 2020, 749, 137370.
 Diffusionreaction approach to electronic relaxation in solution. An alternative simple derivation for two state model. S. Mudra* & A. Chakraborty, Physica A, 2020, 545, 123779.
 2019

 Exact solution of Schrodinger equation for time dependent ultrashort barrier, S. Mudra* & A. Chakraborty, Phys. Scr., 2019, 94, 115227.
 Reactiondiffusion system: Fate of a Gaussian probability distribution on a flat potential with a sink. R. Saravanan* & A. Chakraborty, Physica A, 2019, 536, 120989.
 Understanding the reversible looping kinetics of a long chain polymer molecule in solution with Dirac Delta coupling. M. Ganguly* & A. Chakraborty, Physica A, 2019, 536, 122509.
 Exact diffusion dynamics of a Gaussian distribution in a two state system. R. Saravanan* & A. Chakraborty, Chem. Phys. Lett., 2019, 731, 136567.
 Exploring the role of relaxation time, bond length and length of the polymer chain in the kinetics of endtoend looping. M. Ganguly* & A. Chakraborty, Chem. Phys. Lett., 2019, 733, 136673.