[5] He has developed a non-iterative approximation to coupled-perturbed Kohn-Sham density functional theoretic equations to calculate non-linear properties.
He has also made contributions in the area of reactivity descriptors; he established Hirshfeld population in the calculation of Fukui functions and developed the local hard-soft-acid-base principle for molecular recognition.
[7] Sourav obtained his master's degree from the Indian Institute of Technology (Kanpur) in 1977 and his doctorate from the University of Calcutta.
For open-shell systems, which are marked by a high degree of quasi-degeneracy, he used a multi-determinant description of reference space to formulate a coupled-cluster analytic derivative to compute the non-linear properties.
In 2003, as an alternative to the Kohn–Sham density functional theoretic approach, which solves the coupled-perturbed Kohn–Sham (CPKS) procedure non-iteratively, Sourav formulated a way to obtain the derivative of the KS matrix using the finite field; the density matrix derivative is obtained by a single-step CPKS solution followed by the analytic evaluation of properties.