Many-body effects on graphene conductivity: Quantum Monte Carlo calculations

Many-body effects on graphene conductivity: Quantum Monte Carlo calculations

Benchmark quantum Monte Carlo calculations

Fixed node diffusion Monte Carlo !FN-DMC" atomization energies are calculated for a benchmark set of 55 molecules. Using single determinant trial wave functions, comparison with experiment yields an average absolute deviation of 2.9 kcal/mol, placing this simplest form of FN-DMC roughly at the same level of accuracy as the CCSD!T"/aug-cc-pVQZ method. However, unlike perturbative wave function e...

Ab Initio Geometry and Bright Excitation of Carotenoids: Quantum Monte Carlo and Many Body Green's Function Theory Calculations on Peridinin.

In this letter, we report the singlet ground state structure of the full carotenoid peridinin by means of variational Monte Carlo (VMC) calculations. The VMC relaxed geometry has an average bond length alternation of 0.1165(10) Å, larger than the values obtained by DFT (PBE, B3LYP, and CAM-B3LYP) and shorter than that calculated at the Hartree-Fock (HF) level. TDDFT and EOM-CCSD calculations on...

Quantum Monte Carlo Calculations of Light Nuclei

The goal of ab-initio light-nuclei calculations is to understand nuclei as collections of nucleons interacting with realistic (bare) potentials through reliable solutions of the many-nucleon Schrödinger equation. Such calculations can study binding energies, excitation spectra, relative stability, densities, transition amplitudes, cluster-cluster overlaps, low-energy astrophysical reactions, an...

Linear-scaling quantum Monte Carlo calculations.

A method is presented for using truncated, maximally localized Wannier functions to introduce sparsity into the Slater determinant part of the trial wave function in quantum Monte Carlo calculations. When combined with an efficient numerical evaluation of these localized orbitals, the dominant cost in the calculation, namely, the evaluation of the Slater determinant, scales linearly with system...