Optimization of quantum Monte Carlo wave functions by energy minimization
نویسندگان
چکیده
منابع مشابه
Optimization of quantum Monte Carlo wave functions by energy minimization.
We study three wave function optimization methods based on energy minimization in a variational Monte Carlo framework: the Newton, linear, and perturbative methods. In the Newton method, the parameter variations are calculated from the energy gradient and Hessian, using a reduced variance statistical estimator for the latter. In the linear method, the parameter variations are found by diagonali...
متن کاملOptimization of quantum Monte Carlo wave functions using analytical energy derivatives
An algorithm is proposed to optimize quantum Monte Carlo ~QMC! wave functions based on Newton’s method and analytical computation of the first and second derivatives of the variational energy. This direct application of the variational principle yields significantly lower energy than variance minimization methods when applied to the same trial wave function. Quadratic convergence to the local m...
متن کاملMonte Carlo energy and variance-minimization techniques for optimizing many-body wave functions
We investigate Monte Carlo energy and variance-minimization techniques for optimizing many-body wave functions. Several variants of the basic techniques are studied, including limiting the variations in the weighting factors that arise in correlated sampling estimations of the energy and its variance. We investigate the numerical stability of the techniques and identify two reasons why variance...
متن کاملSpin contamination in quantum Monte Carlo wave functions
The wave function usually employed in quantum Monte Carlo ~QMC! electronic structure calculations is the product of a Jastrow factor and a sum of products of up-spin and down-spin determinants. Typically, a different Jastrow factor is used for paralleland antiparallel-spin electrons in order to satisfy the cusp conditions and thereby ensure that the local energy at electron– electron coincidenc...
متن کاملGeneralized valence bond wave functions in quantum Monte Carlo.
We present a technique for using quantum Monte Carlo (QMC) to obtain high quality energy differences. We use generalized valence bond (GVB) wave functions, for an intuitive approach to capturing the important sources of static correlation, without needing to optimize the orbitals with QMC. Using our modifications to Walker branching and Jastrows, we can then reliably use diffusion quantum Monte...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Journal of Chemical Physics
سال: 2007
ISSN: 0021-9606,1089-7690
DOI: 10.1063/1.2437215