Diptarka Hait

Position: Graduate Student
Office: 48 Gilman Hall
Email: diptarka AT berkeley.edu
CV

Education
S.B. in Chemistry and Physics (2016)
Massachusetts Institute of Technology
Advisor:  Professor Troy Van Voorhis

Research Interests
Development and Assessment of Density Functionals

Historically, functional development had mostly focused on improving prediction of energetics. It has been suggested (Science 355.6320 (2017): 49-52.) that this approach has led to overparametrization of functionals, leading to worse predictions of non-energetic properties like densities.  I am currently investigating the ability of current functionals in predicting density and electrical response properties like polarizibilities, with the ultimate objective of using this information to develop functionals that do not sacrifice prediction of density and related properties merely for the sake of improving energetics .

Development of Selected CI techniques
There has been a recent renaissance in selected configuration interaction (CI) methods on account of the development of Adaptive Sampling CI (ASCI), Heat-bath CI (HCI), Adaptive CI (ACI) etc. I am working with Norm Tubman in the Whaley Group and Daniel Levine on developing and optimizing the ASCI method further, along with applying it to interesting systems.

Collaborations with Experimentalists
I enjoy applying quantum chemistry methods to solve problems experimentalists encounter in their wet (or not so wet) lab research. I have worked on quite varied areas like crossed molecular beams, calculating spin-spin couplings in MOFs, stereoselective synthesis and  predicting UV/Vis spectra.
Feel free to drop me a line if you are an experimentalist who wants to pick a theorist’s brain. I have far too many active commitments to take on a new collaboration at the moment, but I do enjoy pointing people towards (what I think is ) the right direction.

Publications

  1. Well-behaved versus ill-behaved density functionals for single bond dissociation: Separating success from disaster functional by functional for stretched H2 (pdf, arxiv)
    Hait D.*, Rettig A.*, Head-Gordon M.
    Journal of Chemical Physics 2019 150 (9), 094115
  2. Delocalization Errors in Density Functional Theory are Essentially Quadratic in Fractional Occupation Number (arXiv)
    Hait D., Head-Gordon M.
    Journal of Physical Chemistry Letters 2018 9, 6280–6288
  3. Bimolecular Reaction Dynamics in the Phenyl–Silane System: Exploring the Prototype of a Radical Substitution Mechanism (ChemRxiv)
    Lucas M., Thomas A.M., Yang T., Kaiser R.I. , Mebel A.M., Hait D., Head-Gordon M.
    Journal of Physical Chemistry Letters 2018 9 (17), 5135-5142.
  4. How Accurate Are Static Polarizability Predictions from Density Functional Theory? An Assessment over 132 Species at Equilibrium Geometry (ChemRxiv)
    Hait D., Head-Gordon M.
    Physical Chemistry Chemical Physics 2018 20 (30), 19800-19810.
  5. xDH double hybrid functionals can be qualitatively incorrect for non-equilibrium geometries: Dipole moment inversion and barriers to radical-radical association using XYG3 and XYGJ-OS (pdfarxiv)
    Hait D., Head-Gordon M.
    Journal of Chemical Physics 2018 148 (17), 171102.
  6. How accurate is density functional theory at predicting dipole moments? An assessment using a new database of 200 benchmark values (arxiv)
    Hait D., Head-Gordon M.
    Journal of Chemical Theory and Computation 2018 14 (4), 1969–1981.

See CV for publications related to work prior to Berkeley.