Variational principles in quantum Monte Carlo: the troubled story of variance minimization

The formalism relies on a trial wave function whose roles are (i) to initiate and guide the underlying Brownian motion in order to improve the efficiency of the sampling (ii)

Fujuki and Betts [14], and also Nishimori and Nakan- ishi [15] discussed the disappearance of long-range or- der in the study of quantum spin systems on the trian-

"Green's relation" results in a larger variance of the average energy so convergence is not as rapid but the method permits the use of a scaling rela- tion so that

Quantum dynamics calculations of the ground state tunneling splitting and of the zero point energy of malonaldehyde on the full dimensional potential energy surface proposed by Yagi

Uses diffusion Monte Carlo projections of wave functions to construct sequences of non-orthogonal basis sets which are injected into a diagonalisation method. Troubles with precision

Im- portantly, all these studies are characterized by the use of very different wave functions ranging from the simple ansatz of a CI singles wave function to complete active

The most widely used variants of QMC are the variational (VMC) and diffusion Monte Carlo (DMC). Thanks to their favorable scaling with the number of particles and the ease

To get a more quantitative view of the dependence of the CIPSI potential energy curves on the number of determinants selected, we report the results obtained for the three