Sajesh P. Thomas




Sajesh P. Thomas



Assistant Professor


Born: Ernakulam, Kerala
Education: Govt. College Kasaragod (BSc), Mahatma Gandhi University Kottayam, Kerala (MSc)
Ph.D.: IISc Bangalore, Solid state and Structural Chemistry Unit (2008-2013, with Prof. T.N. Guru Row)
Post Doctoral Fellow: The University of Western Australia, Perth, Australia (2013-2017, with Prof. Mark Spackman)
Post Doctoral Fellow: Aarhus University, Denmark (Marie-Curie fellow, 2017-2020, with Prof. Bo B. Iversen)
Assistant Professor(contract): Aarhus University, Denmark (2020-2021)
Assistant Professor: Indian Institute of Technology Delhi, April 2021-present


Group Webpage



Research Interests


Quantum Crystallography and Crystal Engineering

To explore the physical chemistry of molecular solids, our research will bridge two areas: (i) Quantum crystallography and (ii) Crystal engineering. Quantum crystallography is a high-resolution crystallography technique, which provides a way to experimentally obtain quantum chemical wavefunctions of molecules in crystals (termed as 'X-ray wavefunctions') and to probe subtle features of electron/orbital densities, weak interactions and bonding in molecules. Within the discipline of crystal engineering, the detailed knowledge of intermolecular interactions is utilized for the design and formulation of new crystalline forms with useful properties. By combining these two approaches, our research will explore both fundamental and application-oriented problems relevant to molecular materials. The research in our group will involve both experimental and computational work (such as X-ray/neutron diffraction experiments, spectroscopic measurements, data analysis and computational modelling).

Specific research objectives:

(i) Design new solid-state forms of crystalline materials-such as high efficacy forms of pharmaceutical drugs and organic functional materials

(ii) Explore structure-stability-property relations for molecular crystals in terms of intermolecular interactions, associated energies, electrostatics etc.

(iii) Employ a combination of X-ray quantum crystallography, spectroscopic techniques and computational modelling to study solid-state supramolecular chemistry towards applications in crystal engineering



Selected Publications


  1. Bandgap Tuning in Molecular Alloy Crystals Formed by Weak Chalcogen Interactions- Sajesh P Thomas, Reshmi Thomas, Thomas Bjørn E Grønbech, Martin Bondesgaard, Aref H Mamakhel, Victoria Birkedal, Bo B Iversen*, J. Phys. Chem. Lett., 2021, 12, 3059.
  2. Bridging crystal engineering and drug discovery by utilizing intermolecular interactions and molecular shapes in crystals - Peter R. Spackman*, Li-Juan Yu, Craig J. Morton, Michael W. Parker, Charles S. Bond, Mark A. Spackman, Dylan Jayatilaka, Sajesh P. Thomas*, Angew. Chem., 2019, 58, 16780.
  3. Investigation of an unusual crystal habit of hydrochlorothiazide reveals large polar enantiopure domains and a possible crystal nucleation mechanism - Sajesh P. Thomas*, A. Grosjean, G. R. Flematti, A. Karton, A. N. Sobolev, A. J. Edwards, R. O. Piltz, B. B. Iversen, G. A. Koutsantonis, M. A. Spackman,* Angew. Chem. In. Ed., 2019, 131, 10361.
  4. Non-classical synthons: Supramolecular recognition via S...O chalcogen bonding in the molecular complexes of riluzole - Sajesh P. Thomas*, V. Kumar, K. Alhameedi, T. N. Guru Row*, Chem. Eur. J., 2019, 25, 3591.
  5. The elusive structural origin of plastic bending in dimethyl sulfone crystals with quasi-isotropic crystal packing - Sajesh P. Thomas*, Ming W. Shi, George A. Koutsantonis, Dylan Jayatilaka, Alison J Edwards, Mark A Spackman* Angew. Chem. In. Ed. 2017, 56, 8468.