English
Related papers

Related papers: Vibrational spectrum of the H5+ molecule using qua…

200 papers

Using trial wavefunctions prepared on quantum devices to reduce the bias of auxiliary-field quantum Monte Carlo (QC-AFQMC) has established itself as a promising hybrid approach to the simulation of strongly correlated many body systems.…

Quantum Physics · Physics 2024-09-16 Matthew Kiser , Matthias Beuerle , Fedor Simkovic

We present a variational Monte Carlo (VMC) method that works equally well for the ground and the excited states of a quantum system. The method is based on the minimization of the variance of energy, as opposed to the energy itself in…

Computational Physics · Physics 2007-05-23 Imran Khan , Bo Gao

Protonated methane, CH5+, is a highly fluxional molecule with large spatial motions of the hydrogen atoms. The molecule's anharmonic effects and the delocalized wavefunction of the hydrogen atoms significantly affect the excitation spectrum…

Chemical Physics · Physics 2026-02-17 Ruisi Wang , Qi Zhang , Lei Wang

The fundamental ground tone vibration of H2, HD, and D2 is determined to an accuracy of 2 x 10^-4 cm^-1 from Doppler-free laser spectroscopy in the collisionless environment of a molecular beam. This rotationless vibrational splitting is…

We describe and discuss a recently proposed quantum Monte Carlo algorithm to compute the ground-state properties of various systems of interacting fermions. In this method, the ground state is projected from an initial wave function by a…

Condensed Matter · Physics 2009-10-28 Shiwei Zhang , J. Carlson , J. E. Gubernatis

Using a diffusion Monte Carlo algorithm, we calculated the spectra of all possible $S$-wave fully heavy pentaquarks within the framework of the quark model. Our aim was to compare the masses of different spin-color configurations…

High Energy Physics - Phenomenology · Physics 2024-09-09 M. C. Gordillo , J. Segovia , J. M. Alcaraz-Pelegrina

Using the Wang-Landau flat histogram Monte Carlo (FHMC) simulation technique, we were able to study two types of triangulated spherical surface models in which the two-dimensional extrinsic curvature energy is assumed in the Hamiltonian.…

Statistical Mechanics · Physics 2010-09-30 Hiroshi Koibuchi

By Using the variational Monte Carlo (VMC) method, we calculate the 1s{\sigma}_g state energies, the dissociation energies and the binding energies of the hydrogen molecule and its molecular ion in the presence of an aligned magnetic field…

Atomic Physics · Physics 2016-06-29 S. B. Doma , M. Abu-Shady , F. N. El-Gamma , A. A. Amer

We present a scalable Bayesian framework for the analysis of confocal fluorescence spectroscopy data, addressing key limitations in traditional fluorescence correlation spectroscopy methods. Our framework captures molecular motion,…

Numerical Analysis · Mathematics 2024-11-07 Daniel McBride , Ioannis Sgouralis

The phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC) method is a stochastic imaginary-time projection technique for computing ground-state properties of strongly correlated quantum systems, with accuracy that depends critically on…

The vibrational spectra of simple CH$_3^+$-Rg (Rg=He, Ne, Ar, Kr) complexes have been studied by vibrational configuration interaction (VCI) theory relying on multidimensional potential energy surfaces (PES) obtained from explicitly…

Chemical Physics · Physics 2020-09-14 Jan Meisner , Philipp P. Hallmen , Johannes Kästner , Guntram Rauhut

One bottleneck of quantum Monte Carlo (QMC) simulation of strongly correlated electron systems lies at the scaling relation of computational complexity with respect to the system sizes. For generic lattice models of interacting fermions,…

Strongly Correlated Electrons · Physics 2019-02-20 Zi Hong Liu , Xiao Yan Xu , Yang Qi , Kai Sun , Zi Yang Meng

The quantum Monte Carlo (QMC) is one of the most promising many-body electronic structure approaches. It employs stochastic techniques for solving the stationary Schr\" odinger equation and for evaluation of expectation values. The key…

Other Condensed Matter · Physics 2007-12-20 Michal Bajdich

To make useful connections with experimental measurements, correlated electronic structure theories must accurately predict chemical properties in addition to energies. We present a finite-difference based algorithm to compute first-order…

Chemical Physics · Physics 2025-09-24 Leon Otis , Sri Gudivada , Marvin Friede , James Shee

Vibrational-excitation cross sections of ground electronic state of carbon dioxide molecule by electron-impact through the CO2-(2\Pi) shape resonance is considered in the separation of the normal modes approximation. Resonance curves and…

Chemical Physics · Physics 2016-11-01 V. Laporta , J. Tennyson , R. Celiberto

We present a Monte Carlo (MC) code we wrote to simulate the photospheric process and to study the photospheric spectrum above the peak energy. Our simulations were performed with a photon to electron ratio $N_{\gamma}/N_{e} = 10^{5}$, as…

High Energy Astrophysical Phenomena · Physics 2016-01-13 Rodolfo Santana , Patrick Crumley , Roberto A. Hernandez , Pawan Kumar

This topical review describes the methodology of continuum variational and diffusion quantum Monte Carlo calculations. These stochastic methods are based on many-body wave functions and are capable of achieving very high accuracy. The…

Materials Science · Physics 2010-02-11 R. J. Needs , M. D. Towler , N. D. Drummond , P. Lopez Rios

Quantum computers have a potential for solving quantum chemistry problems with higher accuracy than classical computers. Quantum computing quantum Monte Carlo (QC-QMC) is a QMC with a trial state prepared in quantum circuit, which is…

Quantum Physics · Physics 2024-06-07 Shu Kanno , Hajime Nakamura , Takao Kobayashi , Shigeki Gocho , Miho Hatanaka , Naoki Yamamoto , Qi Gao

The rovibrational spectrum of the molecular ion H$_2$CCCH$^+$ was investigated in a 4~K cryogenic ion trap instrument employing the leak-out spectroscopy method. Transitions within the fundamental $\nu_1$ (C-H stretch) and the combination…

Determining the vibrational structure of a molecule is central to fundamental applications in several areas, from atmospheric science to catalysis, fuel combustion modeling, biochemical imaging, and astrochemistry. However, when significant…

Quantum Physics · Physics 2021-12-22 Nicolas P. D. Sawaya , Francesco Paesani , Daniel P. Tabor