I received my Ph.D. in Physics from the University of Wisconsin-Milwaukee under the supervision of Prof. Marius Schmidt and Prof. Peter Schwander. My research was based on X-ray science and crystallography with a focus on the structure determination of biological macromolecules using time-resolved serial crystallography and single-particle imaging at XFELs.

My current research focuses on characterizing nanometer-scale heterogeneity in crystalline/polycrystalline materials based on the propagation of coherent X-rays in such materials. This includes the theoretical and simulation framework of lens-based coherent X-ray scattering along with the development of coherence-enhanced dark-field X-ray microscopy techniques.

Education

• Ph.D. (Physics), University of Wisconsin-Milwaukee (2020)
• M.Sc. (Physics), Tribhuvan University, Nepal (2013)
• B.Sc. (Physics, Statistics, Mathematics), Tribhuvan University, Nepal (2010)

Selected Publications

• M. Carrillo, S. Pandey, J. Sanchez, M. Noda, I. Poudyal, L. Aldama, T. N. Malla, E. Claesson, W.Y. Wahlgren, D. Feliz, V. Šrajer, M. Maj, L. Castillon, S. Iwata, E. Nango, R. Tanaka, T. Tanaka, L. Fangjia, K. Tono, S. Owada, S. Westenhoff, E. A. Stojković, M. Schmidt (2021). ​“High-resolution crystal structures of transient intermediates in the phytochrome photocycle ” Structure 29.7, 743-754.e4
• I. Poudyal, M. Schmidt, and P. Schwander (2020). ​“Single-particle imaging by x-ray free-electron lasers – How many snapshots are needed?” Structural Dynamics 7.2, 024102. 
• S. Pandey*, I. Poudyal*, T.N. Malla* (2020) ​“Pump-Probe Time-Resolved Serial Femtosecond Crystallography at X-ray Free Electron Lasers.” Crystals 10.7, 628 (*corresponding author).
• S. Pandey ^#, R. Bean^#, T. Sato^#, I. Poudyal, J. Bielecki, J. Cruz Villarreal, O. Yefanov, V. Mariani, T. A. White, C. Kupitz, M. Hunter, M. H. Abdellatif, S. Bajt, V. Bondar, A. Echelmeier, D. Doppler, M. Emons, M. Frank, R. Fromme, Y. Gevorkov, G. Giovanetti, M. Jiang, D. Kim, Y. Kim, H. Kirkwood, A. Klimovskaia, J. Knoska, F. H. M. Koua, R. Letrun, S. Lisova, L. Maia, V. Mazalova, D. Meza, T. Michelat, A. Ourmazd, G. Palmer, M. Ramilli, R. Schubert, P. Schwander, A. Silenzi, J. Sztuk-Dambietz, A. Tolstikova, H. N. Chapman, A. Ros, A. Barty, P. Fromme, A. P. Mancuso, M. Schmidt (2019) Time-Resolved Serial Femtosecond Crystallography at the European XFEL. Nature Methods 17.1, 73-78.
• J. Olmos, S. Pandey, J. Martin-Garcia, G. Calvey, A. Katz, J. Knoska, C. Kupitz, M. S. Hunter, M. Liang, D. Oberthuer, O. Yefanov, M. Wiedorn, M. Heyman, M. Holl, K. Pande, A. Barty, M. D. Miller, S. Stern, S. Roy-Chowdhury, J. Coe, N. Nagaratnam, J. Zook, J. Verburgt, T. Norwood, I. Poudyal, D. Xu, J. Koglin, M. H. Seaberg, Y. Zhao, S. Bajt, T. Grant, V. Mariani, G. Nelson, G. Subramanian, E. Bae, R. Fromme, R. Fung, P. Schwander, M. Frank, T. A. White, U. Weierstall, N. Zatsepin, J. Spence, P. Fromme, H. N. Chapman, L. Pollacket, L. Trembley, A. Ourmazd, G. Phillips, M. Schmidt (2018) Authentic Enzyme Intermediates Captured ​“on-the-fly” by Mix-and-Inject Serial Crystallography, BMC-Biology 16 (1), 59.
• N. C. Woitowich, A. S. Halavati, P. Waltz, C. Kupitz, J. Valera, G. Tracy, K.D. Gallagher, E. Claesson, T. Nakana, S. Pandey, G. Nelson, R. Tanaka, E. Nango, E. Mizohata, S. Owada, K. Tono, Y. Joti, A.C. Nugent, H. Patel, A. Mapara, J. Hopkins, P. Duong, D. Bizhga, S.E. Kovaleva, R. St. Peter, C.N. Hernandez, W.B. Ozarowski, S. Roy-Chowdhuri, J-H Yang, P. Edlund, H. Takala, J. Ihalainen, J. Brayshaw, T. Norwood, I. Poudyal, P. Fromme, J.C.H. Spence, K. Moffat, S. Westenhoff, M. Schmidt^*, E. Stojkovic^*(2018) Structural Basis for Light Control of Cell Development as Revealed by Crystal Structures of a Myxobacterial Phytochrome, IUCrJ 5 (5).
• C. Kupitz, J. L. Olmos Jr., M. Holl, L. Tremblay, K. Pande, S. Pandey, D. Oberthür, M. Hunter, M. Liang, A. Aquila, J. Tenboer, G. Calvey, A. Katz, Y. Chen, M.O. Wiedorn, J. Knoska, A. Meents, V. Mariani, T. Norwood, I. Poudyal, T. Grant, M. D. Miller, W. Xu, A. Tolstikova, A. Morgan, M. Metz, J. Martin-Gracia, J.D. Zook, S. Roy-Chowdhury, J. Coe, N. Nagaratnam, D. Meza, R. Fromme, S. Basu, M. Frank, T. White, A. Barty, S. Bajt, O. Yefanov, H.N. Chapman, N. Zatsepin, G. Nelson, U. Weierstall, J. Spence, P. Schwander, L. Pollack, P. Fromme, A. Ourmazd, G.N. Phillips Jr., M. Schmidt (2017) Structural Enzymology Using X-ray Free Electron Lasers, Structural Dynamics 4 (4), 044003.
• P. Edlund, H. Takala, E. Claesson, L. Henry, R. Dods, H. Lehtivuori, M. Panman, K. Pande, T. White, T. Nakane, O. Berntsson, E. Gustavsson, P. Bath, V. Modi, S. Roy-Chowdhury, J. Zook, P. Berntsen, S. Pandey, I. Poudyal, J. Tenboer, C. Kupitz, A. Barty, P. Fromme, J. D. Koralek, T. Tanaka, J. Spence, M. Liang, M. S. Hunter, S. Boutet, E. Nango, K. Moffat, G. Groenhof, J. Ihalainen, E. A. Stojkovic, M. Schmidt^*, S. Westenhoff^* (2016), The room temperature crystal structure of a bacterial phytochrome determined by serial femtosecond crystallography, Scientific reports 6, 35279. 
• I. Poudyal, N.P. Adhikari (2014) Temperature dependence of diffusion coefficient of carbon monoxide in water: A molecular dynamics study, Journal of Molecular Liquids 194, 77-8.