Exact property estimation from diffusion Monte Carlo with minimal stochastic reconfiguration /

Our objective is to develop a diffusion Monte Carlo (DMC) algorithm to estimate the exact expectation values, ($o|^|^o), of multiplicative operators, such as polarizabilities and high-order hyperpolarizabilities, for isolated atoms and molecules. The existing forward-walking pure diffusion Monte Carlo (FW-PDMC) algorithm which attempts this has a serious bias. On the other hand, the DMC algorithm with minimal stochastic reconfiguration provides unbiased estimates of the energies, but the expectation values ($o|^|^) are contaminated by ^, an user specified, approximate wave function, when A does not commute with the Hamiltonian. We modified the latter algorithm to obtain the exact expectation values for these operators, while at the same time eliminating the bias. To compare the efficiency of FW-PDMC and the modified DMC algorithms we calculated simple properties of the H atom, such as various functions of coordinates and polarizabilities. Using three non-exact wave functions, one of moderate quality and the others very crude, in each case the results are within statistical error of the exact values.

Clipping from a Town Council meeting at which estimates of the costs of Railway Line no. 1 and Line no. 2 were submitted by the office of Port Dalhousie and Thorold Railway

Clipping from a Town Council meeting at which estimates of the costs of Railway Line no. 1 and Line no. 2 were submitted by the office of Port Dalhousie and Thorold Railway. The estimate was submitted by S.D. Woodruff and George Rykert, president. There is also a disclaimer in which Calvin Phelps claims to have resigned as director of the Port Dalhousie and Thorold Railway when he discovered that the company had no intention to adhere to the original plan for building and running the road, Aug. 1854.

Chart of Port Dalhousie and Thorold Railway from St. Catharines to Thorold estimates

Chart of Port Dalhousie and Thorold Railway from St. Catharines to Thorold estimates. This document is slightly burnt and torn. Text is slightly affected. It is signed by S.D. Woodruff, Dec. 27, 1856.

Abstract of estimates

Abstract of estimates, June 13, 1856.

Report by Jacob Misner on setting contracts for deepening and clearing ditches and estimates of quantities and costs of marsh drainage

Report by Jacob Misner on setting contracts for deepening and clearing ditches and estimates of quantities and costs of marsh drainage (3 ½ pages, handwritten). This is marked as a copy, July 14, 1855.

Estimates for marsh drainage sent to Dexter Deverardo from S.D. Woodruff for Alexander Cook and Andrew Mains

Estimates for marsh drainage sent to Dexter Deverardo from S.D. Woodruff for Alexander Cook and Andrew Mains, Nov. 30, 1855.

Abstract of estimates given to Andrew Mains for ditching on the main drain of marsh lands for 1855 and 1856

Abstract of estimates given to Andrew Mains for ditching on the main drain of marsh lands for 1855 and 1856. This is signed by S.D. Woodruff, May 1, 1857.

A torn scrap of paper which gives estimates of times worked for Fred Holmes, Joe Simpson, John Simpson, William Baird and William Case

A torn scrap of paper which gives estimates of times worked for Fred Holmes, Joe Simpson, John Simpson, William Baird and William Case. Much of the text is missing. This is signed by Fred Holmes, Dec. 1857.