Aquaporins are integral membrane proteins from a larger family of major intrinsic proteins that formpores in the membrane of biological cells. Aquaporins form tetramers in the cell membrane with eachmonomer acting as a water channel.In this research, the AQP4 tetramer was modeled from its PDBstructure file, then, we have performed the intraction of aquaporin4 in different temperatures (298k,300...

When estimating logistic-normal models, the integral appearing in the marginal likelihood is analytically intractable, so that numerical methods such as GaussHermite quadrature (GH) are needed. When the dimensionality increases, the number of quadrature points becomes too high. A possible solution can be found among the Quasi-Monte Carlo (QMC) methods, because these techniques yield quite good ...

Quantum Monte Carlo (QMC) is among the most accurate ab initio Quantum Chemistry methods available. Furthermore, in stark contrast with comparable methods, it is trivially parallelizable, it requires only a negligible amount of memory, and it’s computational cost scales as only O(N^3). Unfortunately, as a stochastic method, it requires a sizeable number of state space evaluations. We have been ...

Imaginary-time correlation functions calculated by quantum Monte Carlo (QMC) are analyzed using the maximum entropy method (MaxEnt) to determine the ground-state energy and spectral overlap function. In contrast to earlier applications of MaxEnt, the data is obtained from importanced-sampled zero-temperature quantum Monte Carlo simulations. The analysis includes two steps. First, that spectral ...

Submitted for the MAR14 Meeting of The American Physical Society Spins as variables in electronic structure quantum Monte Carlo calculations1 LUBOS MITAS, MINYI ZHU, SHI GUO, North Carolina State University — Current electronic structure quantum Monte Carlo (QMC) methods keep particle spins static in configurations that correspond to spin-space symmetries of calculated states. Here we present a...

On the basis of quantum Monte Carlo (QMC) simulations we study the formation of Mott domains in the one-dimensional Hubbard model with an additional confining potential. We find evidences of quantum critical behavior at the boundaries of the Mott-insulating regions. A local compressibility defined to characterize the local phases exhibits a non-trivial critical exponent on entering the Mott-ins...

Submitted for the MAR06 Meeting of The American Physical Society Quantum Monte Carlo Calculations of Excitations in Hydrogenated Germanium Clusters JORDAN VINCENT, Physics Dept. at UIUC, JEONGNIM KIM, NCSA/MCC at UIUC, RICHARD MARTIN, Physics Dept. at UIUC — Quantum Monte Carlo (QMC) calculations are presented for energies of ground and excited states of Ge atom and hydrogen passivated closed-s...

We consider a mathematical model for polymeric liquids which requires the solution of high-dimensional Fokker-Planck equations related to stochastic differential equations. While Monte-Carlo (MC) methods are classically used to construct approximate solutions in this context, we consider an approach based on QuasiMonte-Carlo (QMC) approximations. Although QMC has proved to be superior to MC in ...

Efficient generation of scenarios is a central problem in evaluating the expected value of a random function in the stochastic optimization. We study the use of sparse grid scenario generation method for this purpose. We show that this method is uniformly convergent, hence, also epi-convergent. We numerically compare the performance of the sparse grid method with several Quasi Monte Carlo (QMC)...

We review the basic principles of quasi-Monte Carlo (QMC) methods, the randomizations that turn them into variance-reduction techniques, the integration error and variance bounds obtained in terms of QMC point set discrepancy and variation of the integrand, and the main classes of point set constructions: lattice rules, digital nets, and permutations in different bases. QMC methods are designed...