Spectroscopic data for the LiH molecule from pseudopotential quantum Monte Carlo calculations

Abstract

Quantum Monte Carlo and quantum chemistry techniques are used to investigate pseudopotential models of the lithium hydride (LiH) molecule. Interatomic potentials are calculated and tested by comparing with the experimental spectroscopic constants and well depth. Two recently-developed pseudopotentials are tested, and the effects of introducing a Li core polarization potential are investigated. The calculations are sufficiently accurate to isolate the errors from the pseudopotentials and core polarization potential. Core-valence correlation and core relaxation are found to be important in determining the interatomic potential.

Low-pressure phase diagram of crystalline benzene from quantum Monte Carlo

“…3 Their results are obtained by means of infrared spectroscopy and X-ray analysis under high pressure. The P2 1 /c phase is stable up to pressures [20][21][22][23][24][25] GPa. This phase diagram only consists of two phases (I and II), and this same result has been reported by other experiments.…”

“…In this work, we will show that quantum Monte Carlo (QMC) is an alternative efficient approach to achieve or surpass such accuracy in benzene crystals, as we previously demonstrated for the benzene dimer. 16 Quantum Monte Carlo (QMC), which approximately solves the electronic Schrödinger equation stochastically, 17 can yield highly accurate energies for atoms, 18,19 molecules, [20][21][22] and crystals. [23][24][25] Previous studies have shown that diffusion quantum Monte Carlo (DMC) can provide accurate energies for noncovalent interactions systems.…”

High-pressure hydrogen sulfide by diffusion quantum Monte Carlo

“…4,[47][48][49] Therefore, in this paper we revisit the stability of the individual products originating from the various proposed decompositions of H 2 S for pressures above 150 GPa by means of highly accurate diffusion Monte Carlo (DMC) simulations. Using the DMC method, 50,51 the electronic manybody Schrödinger equation is solved stochastically, which have yielded very accurate total energies for atoms, 52,53 molecules, [54][55][56] and crystals [57][58][59] including hydrogen-rich materials at very high pressure. 5,[60][61][62] …”

Electronic structure and time-dependent description of rotational predissociation of LiH

“…Gadea and coworkers calculated potential energy curves 2,6,7,8 , radial couplings 9 , nonaa Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Naru-diabatic energy shifts 10 as well as the LiH formation by radiative association in ion collisions 11 . Results of several other calculations, including semiempirical and ab initio approaches to describe important physical and chemical properties of LiH are available 12,13,14,15,16,17,18,19,20,21,22 . Calculations related to LiH are also used in the description of ultracold polar molecules formation in a single quantum state (e.g.…”