IIT Mandi’s Distinguished Professor Gautam R. Desiraju Receives 14th Ewald Prize

He has Received this Global Honour for Pioneering Crystal Engineering Work which can help in optimizing drug solubility, stability, and mechanical properties without altering the active drug molecule itself

Professor Emeritus Gautam R. Desiraju has been
awarded the 14th Ewald Prize by the International Union of Crystallography (IUCr)
for pioneering the subject of crystal engineering and the supramolecular synthon
concept, and for establishing the structural significance of weak hydrogen bonding
and halogen bonding in molecular crystals and biology. The Ewald Prize, awarded
once every three years at the International Congress of Crystallography, recognises
outstanding contributions to the science of crystallography, and the 2026 laureate, on
11 th August 2026, Gautam R. Desiraju, has been honoured at the IUCr Congress in
Calgary, Canada.
Desiraju — an Emeritus Professor at the Indian Institute of Science, Bengaluru, and
a Distinguished Professor at IKSMHA, IIT Mandi, among other affiliations — has
described the honour in characteristically direct terms.
Reflecting on the award, Professor Emeritus Gautam R. Desiraju said, “The
Ewald Prize is widely considered the highest accolade a structural chemist or
biologist can receive, short of the Nobel Prize, singling out the complete
professionalism of its rigorous and confidential selection process.”
Speaking upon this Prof. Laxmidhar Behera, Director, IIT Mandi, said, “Professor
Desiraju’s Ewald Prize is a matter of immense pride for IIT Mandi and Indian
science. His pioneering work in crystal engineering has transformed our
understanding of molecular interactions and opened new possibilities in
pharmaceuticals and advanced materials. We congratulate him on this well-deserved
global recognition.”
To mark the award, Desiraju has published a lead article in IUCrJ (Volume 13, Part 5,
September 2026) titled “Crystal clear. Engineering complexity,” an open-access,
first-person retrospective on the field he helped found. The paper accompanies the
prize and forms part of a collection tied to the IUCr 2026 Congress.
From “anomalous” crystals to a design science
The article traces a scientific journey that began during Desiraju’s PhD at the
University of Illinois, where he was struck by a deceptively simple question: why do
crystals adopt the structures they do? At the time, the prevailing view — associated
with the physicist Kitaigorodskii — held that organic crystals were governed chiefly
by close packing. Desiraju’s insight was to treat the exceptions as the key.

His attention turned to weak intermolecular forces, particularly the C—H···O
interaction, which he and Thomas Steiner ultimately validated as a genuine weak
hydrogen bond in their 1999 book. Once dismissed as insignificant, these
interactions are now recognised as structurally and functionally important in both
small-molecule crystals and biological systems.
The supramolecular synthon
The conceptual heart of the article — and of Desiraju’s legacy — is the
supramolecular synthon, a term he defined in a landmark 1995 review. Borrowing
from Corey’s retrosynthetic logic in molecular synthesis, Desiraju reframed the
molecular crystal itself as a synthetic target, one that could be “disconnected” into
structural modules assembled through predictable intermolecular interactions. This
move, more than any other, positioned crystal engineering within the chemical
mainstream as a form of synthesis rather than mere structural description.
The paper walks through how this thinking scaled up: from binary and ternary
cocrystals built on insulated, hierarchically arranged synthons, to quaternary and
even five- and six-component molecular crystals — what Desiraju calls the “Mount
Everest of supramolecular solid state synthesis.”
Real-world payoffs and open questions
The article connects these ideas to tangible applications, most notably
pharmaceutical cocrystals, which improve the solubility and bioavailability of poorly
water-soluble drugs and have yielded around half a dozen marketed medicines built
on crystal-engineered logic. It also covers polymorphism and crystal structure
prediction — where Desiraju argues AI may fully solve the prediction problem within
five to ten years — and a newer sub-branch on mechanically deformable crystals
that bend, shear, or self-heal.
A holistic turn
The essay closes on a philosophical note that will resonate with readers interested in
Indian Knowledge Systems. Desiraju frames the molecular crystal not as an
assembly of parts but as a complex, holistic system, explicitly setting the integrative
philosophies of older societies alongside Western reductionism. He argues that a
functional crystal depends on a synergy between the rigidity of strong bonds and the
adaptive subtlety of weak ones — and, extending the metaphor outward, on the
“essential oneness” of a shared human intellect across cultures.
With more than 475 publications and over 80,000 citations, and having served as
President of the IUCr from 2011 to 2014, Desiraju’s contributions have had a
profound influence on structural chemistry and crystallography worldwide. The Ewald
Prize now formally recognises a body of work that transformed crystal engineering
from a curiosity into a predictive, design-oriented discipline.