Closed-shell variational quantum Monte Carlo simulation for the electric dipole moment calculation of hydrazine molecule using casino-code

Abstract

A quantum Monte Carlo (QMC) study of the electric dipole moment of hydrazine molecule using CASINO-code is presented. The variational quantum Monte Carlo (VQMC) technique used in this work employed the restricted Hartree-Fock (RHF) scheme. The components dependence of the electric dipole moment from the QMC technique is studied with a single determinant Slater-Jastrow trial wave-function obtained from the Hartree-Fock orbitals. The simulation requires that the configurations must evolve on the time scale of the electronic motion, and after equilibration, the estimated effective timestep be obtained. From our result, though the VQMC method showed much fluctuation, the technique calculated the electric dipole moment of hydrazine molecule as 2.0 D, which is in closer agreement with 1.85 D experimental value than others in literature. Thus, the result from this study is found to be precisely approaching the required order of chemical accuracy.

Keywords: CASINO code, Electric dipole moment, Hydrazine (N2H4) molecule, QMC, VQMC