Research Interests

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My research inter­ests focus on con­nect­ing ab ini­tio elec­tronic struc­ture meth­ods with ther­mo­dy­namic and kinetic prop­er­ties of mat­ter. I use state-of-the-art elec­tronic struc­ture meth­ods in com­bi­na­tion with a wide vari­ety of tech­niques from quan­tum mechan­ics to mol­e­c­u­lar dynam­ics, to solve rel­e­vant prob­lems in chem­istry, bio­physics, and mate­ri­als science.

FIRST-PRINCIPLES SIMULATIONS
The pre­dic­tive capa­bil­i­ties of mod­ern the­o­ret­i­cal com­pu­ta­tional meth­ods are sig­nif­i­cantly impact­ing chem­i­cal sci­ences. A pos­si­ble exam­ple of this from my own research has been the use of first-principles elec­tronic struc­ture meth­ods to pre­dict struc­ture and red-ox prop­er­ties of fer­rous cen­ter and sys­tems of envi­ron­men­tal inter­est e.g. nitroben­zene and trini­tro­toluene. Although the exper­i­men­tal evi­dences are still lim­ited, the iron (II) oxo-species are one of the most attrac­tive NACs-reducing agents being extremely cheap and envi­ron­men­tally clean.¹ 1. a) I. Zil­ber­berg, M. Ilchenko, O. Isayev, L. Gorb, J. Leszczyn­ski. J. Phys. Chem. A, 2004, 108, 4878.
b) O. Isayev, L. Gorb, I. Zil­ber­berg, J. Leszczyn­ski. J. Phys. Chem. A, 2007, 111, 3571. On the other hand first-principles sim­u­la­tions applic­a­ble to a wide vari­ety of prob­lems, rang­ing from high-pressure physics to sol­va­tion chem­istry, nan­otech­nol­ogy, and mol­e­c­u­lar biol­ogy. Of par­tic­u­lar inter­est to me is the struc­ture and dynam­ics of nucleic acid bases in water, mech­a­nism of catal­y­sis on fer­rous and fer­ric cen­ters, reac­tiv­ity and trans­for­ma­tions of sub­sti­tuted nor­bornene derivatives.

TOWARDS HIGH ACCURACY
Cur­rently I am inves­ti­gat­ing the use of high-level post Hartree-Fock meth­ods in the con­text of refin­ing the pro­ce­dure for cal­cu­la­tions of Gibbs free energy with rel­a­tive accu­racy less than 1 kcal/mol.² 2. O. Isayev, L. Gorb, J. Leszczyn­ski. J. Comp. Chem. 2007, 28, 1598. By com­bin­ing these approaches together; by ana­lyz­ing the effects of elec­tron cor­re­la­tion, basis set size, and anhar­monic­ity the new eco­nomic way to reach chem­i­cal accu­racy in the cal­cu­la­tions of the ther­mo­dy­namic para­me­ters for inter­mol­e­c­u­lar inter­ac­tions is pro­posed. I am presently employ­ing this method­ol­ogy for mod­el­ing of sys­tems of bio­log­i­cal and envi­ron­men­tal inter­est. Also, I am explor­ing bridg­ing of ther­mo­dy­namic inte­gra­tion approach with Car-Parrinello mol­e­c­u­lar dynam­ics method for the same purpose.

HIGH-PERFORMANCE COMPUTING (HPC)
With the emer­gence of the­o­ret­i­cal chem­istry, bio­physics and HPC, the sci­en­tific and tech­ni­cal oppor­tu­ni­ties in this field are enor­mous. As part of col­lab­o­ra­tion with the Army High Per­for­mance Com­put­ing Research Cen­ter (AHPCRC) my efforts are devoted to bench­mark­ing and performance/functionality enhance­ments com­pu­ta­tional chem­istry codes (e.g. CPMD) on the new Cray X1E and XT3 super­com­put­ers, Opteron Linux Beowulf clus­ter sys­tems. As part of col­lab­o­ra­tion with the Mis­sis­sippi Cen­ter for Super­com­put­ing Research (MCSR) I have been involved into test­ing, bench­mark­ing and tun­ing some sci­en­tific appli­ca­tions for the 198 CPUs SGI Altix 3700 global shared-memory system.