Collaborative Efforts Propel Quantum Monte Carlo Project Forward

For Dr Stuart Rothstein, professor of chemistry and physics at Brock University, quantum Monte Carlo developments have never been more attainable. Thanks to the speed of high performance computers at the University of Alberta, made available through MACI, he has been able to develop new quantum Monte Carlo methods, assisting in the theoretical determination of atomic and molecular properties.

Quantum Monte Carlo methods have been developed to complement traditional methods. Quantum Monte Carlo methods have many advantages which include rapid convergence to the exact electron distribution, easy incorporation of features of exact wave functions stemming from electron to electron and electron to nuclear cusps, and explicit dependence on inter-electronic distance. 

Rothstein’s goal is to take these advantages and apply them, by providing a systemized methodology to estimate non-trivial physical properties of atoms and molecules, such as high order polarizabilities and hyperpolarizabilities. Potentially, these properties will be fundamental in determining the molecular geometrics of products of chemical reactions.

Rothstein attributes much of his success to having access to high performance technology. As the computing facilities at Brock are minimal there would be no way his group could develop new quantum Monte Carlo methodologies using exclusively in-house computers.  Without access to MACI resources, Rothstein would have to do purely theoretical research and abandon algorithm development all together, losing wider research applicability.

srothste@abacus.ac.BrockU.CA

http://chemiris.labs.brocku.ca/~chemweb/faculty/rothstein/

Selected Publications

M. Snajdr and S.M. Rothstein. How accurate are physical properties estimated from variance-optimized wave functions? Accurate physical properties for H2, He, and LiH, J. Chem. Phys 112, 4935-4941, 2000.

M. Hornik, M. Snajdr, and S.M. Rothstein. Estimating the overlap of an approximate with the exact wave function by quantum Monte Carlo Methods, J. Chem. Phys. 113, 2496-3498, 2000.

M. Snajdr, J. Dwyer, and S.M. Rothstein. Histogram Filtering as a Tool in Global Optmization of Many-body Wave Functions, J. Chem. Phys. 111,9971-9981 (1999).

V.N. Staroverov,  P.Langfelder, and  S.M. Rothstein Monte Carlo Study of Core-valence Separation Schemes, J. Chem. Phys. 108, 2873-2885, 1998.

P.Langfelder, S.M.Rothstein, and J. Vrbik. Diffusion Quantum Monte Carlo Calculation of Nondifferential Properties for Atomic Ground States, J. Chem. Phys. 107, 8525-8535, 1997.

S.M. Rothstein, All-Electron Monte Carlo Calculations on Heavy Atom Systems, in Recent Advances in Quantum Monte Carlo Methods, ed. by W.A. Lester, Jr. pp 181-187, World Scientific, Singapore, 1997.

P. Langfelder, S.M. Rothstein, and J. Vrbik. Diffusion Quantum Monte Carlo Calculation of Nondifferential Properties for Atomic Ground States, J. Chem. Phys. 107, 8525-8535, 1997.