Dr. Biswajit Sadhu
ABOUT ME
I am a computational chemist and data scientist. I am working as Assistant Professor at Homi Bhabha National Institute (HBNI), Mumbai. I am also serving as scientist at Bhabha Atomic Research Center (BARC), Mumbai, India. I have expertise in theoretical chemistry, topological data analysis, machine learning and deep learning methods. My research interest lies on the application of data-science based methods in the domain of chemical, environmental, material and nuclear science. I use a range of techniques including but not limited to quantum mechanics, molecular dynamics, metadynamics along with graph theoretic analyses tools for the research projects. I am passionate about exploring new data analysis methods, and open to collaborative projects.
publications
[34] Sadhu, B.;* Sadhu, T.; Anand, S. RadDQN: a Deep Q Learning-based Architecture for Finding Time-efficient Minimum Radiation Exposure Pathway, arXiv preprint arXiv:2402.00468
[33] Kumar, P., Dumpala, R.M.R., Telmore, V.M., Sadhu, B., Sundararajan, M., Yadav, A.K., Bhattacharyya, D. and George, J.P., 2024. Thorium Complexation with Aliphatic and Aromatic Hydroxycarboxylates: A Combined Experimental and Theoretical Study. ACS Omega. 9, 25, 27289–27299, 2024.
[32] Borthakur, I.; Nandi, S.; Bilora, Y.; Sadhu, B.; Kundu, S. Reductive Aminomethylation Using Ammonium Formate and Methanol as N1 and C1 Source: Direct Synthesis of Mono-and Di-Methylated Amines, ACS Catalysis 14, 5847-5857, 2024.
[31] Story, B.; Sadhu, B.; Adams, H.; Clark, A. E. Additive energy functions have predictable landscape topologies, J. Chem. Phys., 158, 164104, 2023.
[30] Sadhu, B.;* & Clark, A. E. Modulating Aggregation in Microemulsions: The Dispersion by Competitive Intermolecular Interaction Model. J. Phys. Chem. Lett., 13, 10981. 2022.
[29] Sadhu, B.;* & Clark, A. E. (2021). “ Molecular Dynamics and Network Analysis Reveal the Contrasting Roles of Polar Solutes Within Organic Phase Amphiphile Aggregation.” J. Mol. Liq, 359, 119226, 2022.
[28] Sharma, S.; Das, D.; Sadhu, B.; & Sharma, N. “Synthesis, characterization, and biological activity of oxidovanadium (IV) hydroxamate complexes supported by density functional theory.” J. Coord. Chem. 75, 689, 2022
[27] Chattaraj, S., Bhattacharyya, A., & Sadhu, B.*. Role of O Substitution in Expanded Porphyrins on Uranyl Complexation: Orbital-and Density-Based Analyses. Inorganic Chemistry. 60, 20, 15351–15363, 2021.
[26] Servis, M. J.; Sadhu, B.;* Soderholm, L.; Clark. A. E. "Amphiphile Conformation Impacts Aggregate Morphology and Solution Structure Across Multiple Lengthscales." Journal of Molecular Liquids, 117743, 2021. (*co-first author)
[25] Patra, K., Sadhu, B., Sengupta, A., Patil, C. B., Mishra, R. K., & Kaushik, C. P. (2021). “Achieving highly efficient and selective cesium extraction using 1, 3-di-octyloxycalix [4] arene-crown-6 in n-octanol based solvent system: experimental and DFT investigation.” RSC Advances, 11, 21323-21331, 2021.
[24] Das, D.; Kannan, S.; Kumar, M.; Sadhu, B.; & Kumbhare, L. B.. “Synthesis, photophysical properties and catalytic activity of Ƙ3-SCS pincer palladium (II) complex of N, N'-di-tert-butylbenzene-1, 3-dicarbothioamide supported by DFT analysis.” ChemRxiv, 2021.; Inorganic Chimica Acta (Accepted)
[23] Kumar, N.; Sadhu, B.; Clark, A. E. “Essential Aspects of Solvent Effects and Solution Conditions Upon the Modeling and Simulation of Lanthanide and Actinide Complexes, in Computational Actinide and Lanthanide Chemistry,” ed. Windus, T.; Pederson, C.; Penchoff, D. ACS Books, Rare Earth Elements and Actinides: Progress in Computational Science Applications, Book Chapter 12, 249-276, 2021.
[22] Sadhu, B.;* Dolg, M. Kulkarni, M. S. "Periodic trends and complexation chemistry of tetravalent actinide ions with a potential actinide decorporation agent 5‐LIO(Me‐3,2‐HOPO): A relativistic density functional theory exploration" Journal of Computational Chemistry, 2020, 41, 1427-1435.
[21] Patil, Y. A.; Sadhu, B.; Boraste, D. R.; Borkar, A. L.; Shankarling, G."Utilization of Cucurbit [6] uril as an effective adsorbent for the remediation of Phthalocyanine and Procion golden yellow dyes" Journal of Molecular Structure, 2020,1202, 127278.
[20] Sadhu, B.;* Dolg, M. "Enhancing Actinide(III) over Lanthanide(III) Selectivity through Hard-by-Soft Donor Substitution: Exploitation and Implication of Near-Degeneracy Driven Covalency" Inorganic Chemistry, 2019, ASAP .
[19] Ali, M.; Sadhu, B.; Boda, A.; Tiwari, N.; Das, A.; Ali, Sk. M.; Bhattacharya, D.; Pandey, B. N.; Kumar, A. “Thorium decorporation efficacy of rationally-selected biocompatible compounds with relevance to human applications.”Journal of hazardous materials 2019, 365, 952-961.
[18] Sadhu, B.;* Mishra, V. “The coordination chemistry of lanthanide and actinide metal ions with hydroxypyridinone-based decorporation agents: orbital and density based analyses.”Dalton transactions2018,47, 16603-16615.
[17] Sadhu, B.; Sundararajan, M.; Bandyopadhyay, T. “Selective Separation of Strontium with Multitopic Ion-pair Receptor: A DFT exploration.”International Journal of Quantum Chemistry, 2017, 117, e25370. (Selected as Cover Page Article)
[16] Sadhu, B.; Sundararajan, M.; Bandyopadhyay, T.“Divalent Ions are Potential Permeating Blockers of the non-selective NaK ion Channel: Combined QM and MD based Investigations.” Physical Chemistry Chemical Physics. 2017,19, 27611-27622.
[15] Kannan, S.; Kumar, M.; Sadhu, B.; Jaccob, M.; Sundararajan, M. “Unusual intramolecular CH…O Hydrogen Bonding Interaction between a Sterically bulky Amide and Uranyl Oxygen.”Dalton Transactions 2017, 46, 16939-16946.
[14] Kumar, P.; Jaison, P. G.; Telmore, V. M.; Sadhu, B.; Sundararajan, M.; “Speciation of Uranium-Mandelic Acid Complexes using Electrospray Ionization Mass Spectrometry and Density Functional Theory”, Rapid Communication in Mass Spectrometry 2017, 31, 561-571
[13] Khungar, B.; Roy, A.; Kumar, A.; Sadhu, B.; Sundararajan, M. “Predicting the Redox Properties of Uranyl Complexes using Electronic Structure Calculations,”International Journal of Quantum Chemistry2017, DOI 10.1002/qua.25370.
[12] Vats, B. G.; Das, D.; Sadhu, B.; Pius, I. C.; Noronha, D.; Kannan, S.; Sundararajan, M. "Selective Recognition of Uranyl ion from Bulk of Thorium (IV) and Lanthanide(III) ions by tetraalkyl Urea: A Combined Experimental and Quantum Chemical Study."Dalton transactions. 2016, 45, 10319-10325.
[11] Mudliar, N. H.; Sadhu, B.; Pettiwala, A. M.; Singh, P. K.; “Evaluation of an Ultrafast Molecular Rotor, Auramine O, as a Fluorescent Amyloid Marker.”Journal of Physical Chemistry B2016, 120, 10496-10507.
[10] Kumar, P.; Jaison, P. G.; Telmore, V. M.; Alamelu, D.; Aggarwal, S. K.; Sadhu, B.; Sundararajan, M. "Gas phase Reactions of Uranyl with α-hydroxyisobutyric Acid using Electrospray Ionization Mass Spectrometry and Density Functional Theory." Journal of Radioanalytical and Nuclear Chemistry. 2016, 308,303-310.
[9] Sadhu, B.; Sundararajan, M.; Bandyopadhyay, T. "Efficient Separation Of Europium Over Americium Using Cucurbit-[5]-uril Through A Cooperative Cation Assisted Anion Binding Mechanism: A Relativistic DFT Based investigation" Inorganic chemistry, 2016, 55, 598-609.
[8] Sadhu, B.; Sundararajan, M. "Asn47 and Phe114 Modulates the Inner Sphere Reorganization Energies of Type Zero Copper Proteins: Insights from Quantum Chemical Calculations."Physical Chemistry Chemical Physics.2016, 18, 16748-16756.
[7] Sadhu, B.; Sundararajan, M.; and Bandyopadhyay, T. "Selectivity of Singly Permeating Ion in Nonselective NaK Channel: A Combined QM and MD Based Investigations."The Journal of Physical Chemistry B 2015, 119, 12783-12797.
[6] Sadhu, B.; Sundararajan, M.; and Bandyopadhyay, T. "Water-Mediated Differential Binding of Strontium and Cesium Cations in Fulvic Acid."The Journal of Physical Chemistry B2015, 119, 10989–10997.
[5] Sadhu, B.; Sundararajan, M.; Velmurugan, G.; Venuvanalingam, P. "Elucidating the Structures and Cooperative Binding Mechanism of Cesium Salts to Multitopic Ion-Pair Receptor through Density Functional Theory Calculations." Dalton Transactions, 2015, 44, 15450-15462.
[4] Verma, P. K.; Kumari, N.; Pathak, P. N.; Sadhu, B.; Sundararajan, M.; Aswal, V. K.; Mohapatra, P. K. "Investigations on preferential Pu (IV) extraction over U (VI) by N, N-dihexyloctanamide versus tri-n-butyl phosphate: evidence through small angle neutron scattering and DFT studies."The Journal of Physical Chemistry A 2014, 118, 3996–4004.
[3] Verma, P. K.; Pathak, P. N.; Kumari, N.; Sadhu, B.; Sundararajan, M.; Aswal, V. K.; and Mohapatra, P. K. "Effect of Successive Alkylation of N, N-Dialkyl Amides on the Complexation Behavior of Uranium and Thorium: Solvent Extraction, Small Angle Neutron Scattering, and Computational Studies."The Journal of Physical Chemistry B2014,118, 14388-14396.
[2] Verma, P. K.; Pathak, P. N.; Mohapatra, P. K.;Aswal, V. K.; Sadhu, B.; Sundararajan, M. "An insight into third-phase formation during the extraction of thorium nitrate: evidence for aggregate formation from small-angle neutron scattering and validation by computational studies." The Journal of Physical Chemistry B2014,117, 9821-9828.
[1] Khorwal, V.; Sadhu, B.; Dey, A.; Sundararajan, M.; and Datta, A. "Modulation of Protonation–Deprotonation Processes of 2-(4′-Pyridyl) benzimidazole in Its Inclusion Complexes with Cyclodextrins."The Journal of Physical Chemistry B2013, 117, 8603-8610.
Talks
[8] “Solvation-induced change in Conformational Ensemble Modulates Amphiphile Self-Assembly”, CTTC, 2022, BARC, Mumbai.
[7] “Finding Time-efficient Optimized Pathway with Minimum Radiation Exposure using Deep Reinforcement Learning” AOCRP6, 2022, Nehru Centre, Worli, Mumbai, India.
[6] “How phase-modifier works in avoiding third-phase formation? Insight from graph-theoretic analyses and molecular dynamics.” ACS Fall Meeting 2021, Atlanta, Georgia, USA.
[5] “Actinide-Lanthanide Selectivity by Soft-Hard Donor Centre Strategy: Exploitation of Near-Degeneracy Driven Covalency” Indian Science Congress-2019, LPU, India.
[4] “Multiscale Modeling on Binding and Translocation of Radionuclide Metals” Institute for Theoretical Chemistry, University of Cologne, Germany, 2018.
[3] “Binding and Transport of Radionuclides in Natural and Synthetic Environment”Award Ceremony,Indian Association of Nuclear Chemists and Allied Scientists, Mumbai, BARC, India, 2018.
[2] "Water mediated differential binding of strontium and cesium cations in soil organic matter" 15th International Conference on the Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere. (MIGRATION). LANL, Santa Fe Community Convention Center, Santa Fe NM, USA, 2015.
[1] "Theoretical Prediction of Speciation of Radionuclide Iodo anion to Soil Organic Matter."
AWARDS
(a) “INSA-DFG Bilateral Exchange Fellowship-2018” to work as visiting scientist at University of Cologne, Germany with Prof. Dr. Michael Dolg.
(b) “DAE Special Achievement Award” in Science, Department of Atomic Energy, Mumbai, 2018.
(c) “Young Scientist Award-2017” from Department of Atomic Energy, India.
Field: Mechanistic Insight on Binding Behaviour of Radionuclides using multiscale modelling approach.
(d) “Prof. H. J. Arnikar Best Ph.D Thesis Award” (2017), IANCAS, India.
(e)“Travelling Fellowship” from Centre for International Cooperation in Science (CICS) to give contributory talk at MIGRATION2015 conference at LANL, Santa Fe Community Convention Center, Santa Fe NM, USA, 2015.
(f) "Outstanding Student Award" for M.Tech Thesis (2015), Homi Bhabha National Institute, India.
Visiting scientisT
May-July 2018, Institute for Theoretical Chemistry, University of Cologne, Germany.
Supervisor: Prof. Dr. Michael Dolg
Topic: Unravelling covalency in actinide and lanthanide complexes.
Awarded Grant: INSA-DFG(Germany) bilateral exchange fellowship.
Postdoctoral experience
Feb 2020- Feb 2022, Washington State University, USA.
Topic: a) Graph theoretic approach on understanding the self-assembly of extractant molecules.
d) Development of algorithms and methods for deciphering the underlying kinetics and thermodynamics of the complex liquid-based systems.
c) Extraction of topological features using persistence homology-based approach.
d) Feature vector optimization of LLE extractants for machine and deep learning applications.
e) Application of dimension reduction techniques on understanding the dynamic coupled coherent features of electron density transport.
Supervisor: Prof. Dr. Aurora Clark, Professor, Director Center for Institutional Research Computing, WSU, Laboratory Fellow, Pacific Northwest National Laboratory,
ACS, APS and AAAS Fellow
Research areas
(a) Data science-based investigations on understanding self-assembly of extractant molecules.
(b) Feature-extraction and optimization for machine- and deep-learning applications.
(c) Development of methods and algorithms todecipher the underlying mechanistic processes using Graph theory, Persistent Homology and Markov Modelling.
(d) Electronic Structure Calculations on Ln/An complexation chemistry.
(e) MD and QM studies on Ln/Anbinding mechanism to biological and synthetic receptors.
(f) Binding and translocation studies of metals in natural and synthetic media using non-equilibrium and equilibrium simulations.
(g) Computer aided design and development of molecular systems for bioremediation, extraction and decorporation of metal ions.
(h) Dimension reduction methods
(i) Application of deep reinforcement learning (DRL) in finding time-efficient minimum radiation exposure pathway in radiation contaminated zone.
(j) AI driven feature extraction from experimental spectra.
coding EXPERTISE
Python (Have acquired extensive coding experience in last 12 years.)
Expertise in pytorch for deep learning application.
Ph.D Students
1) Amit Silswal (2023-present)
Topic: Information-enriched Transformation of Low Resolution Spectra of Radiation Detector Using Machine and Deep Learning Methods
SOME RESEARCH HIGHLIGHTS
COVER PAGE ARTICLE AT IJQC:
using free energy corrected density functional theory, we have proposed a two-step Sr2+ extraction methodology in nitrate media in the presence of interfering Ca2+ ion using a multitopic ion-pair receptor.
Enhancing Actinide(III) over Lanthanide(III) Selectivity through Hard-by-Soft Donor Substitution: Exploitation and Implication of Near-Degeneracy-Driven Covalency.
(Inorg. Chem. 2019, 58, 15, 9738–9748)
Relativistic density functional theory study along with orbital- and density-based analyses deciphers that the incorporation of soft sulfur-donor centers within a hard-donor-based ligand exploits near-degeneracy-driven covalency to infuse selectivity for actinide(III) over lanthanide(III) ions. However, such enhanced covalency comes at the expense of a reduced electrostatic interaction and only plays a negative effect on providing additional thermodynamic stabilization of the complexes.
Modulating Aggregation in Microemulsions: The Dispersion by Competitive Intermolecular Interaction Model.
(J. Phys. Chem. Lett. 2022, 13, 47, 10981–10987)
A phenomenological model has been developed for the mechanism of action of phase modifiers as additives that control aggregation phenomena within water-in-oil emulsions. The “Dispersion by Competitive Intermolecular Interaction” model (DCI) explicitly considers the strength and prevalence of different intermolecular interactions that influence the molecular association of amphiphiles, the resulting distribution of aggregate size, and interaggregate interactions that influence phase phenomena.
Role of O Substitution in Expanded Porphyrins on Uranyl Complexation: Orbital- and Density-Based Analyses.
(Inorg. Chem. 2021, 60, 20, 15351–15363)
(link)
Orbital- and density-based investigations on the bonding characteristics of the uranyl ion with expanded porphyrins in a mixed-donor (O and N) environment suggest that despite having more numbers of mixed molecular orbitals with O, uranyl prefers binding with N due to the variation in overlap amplitudes. U−N/O bonds at the equatorial plane carry signatures of near-degeneracy-driven covalency. The replacement of N donors with O triggers uranyl to have a better bonding interaction with the remaining N donors at the ligand cavity.