Excited States of Weakly Bound Bosonic Clusters:  Discrete Variable Representation and Quantum Monte Carlo†

2006 ◽  
Vol 110 (16) ◽  
pp. 5391-5394 ◽  
Author(s):  
M. P. Nightingale ◽  
Pierre-Nicholas Roy
Keyword(s):  
Monte Carlo ◽  
Excited States ◽  
Quantum Monte Carlo ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Weakly Bound ◽  
Variable Representation

scholarly journals Determinação de Constantes Espectroscópicas Rovibracionais via Monte Carlo Quântico

2020 ◽  
Author(s):  
Cassius M. C. Carvalho ◽  
Ricardo Gargano ◽  
José Roberto S. Politi ◽  
João B. L. Martins
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
Spectroscopic Properties ◽  
Spectroscopic Constants ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Hartree Fock ◽  
Diatomic Systems ◽  
Variable Representation

This work evaluated the efficiency of the Diffusion quantum Monte Carlo (DMC) method in determining potential energy curves (PECs) for diatomic systems. This evaluation was performed by determining rovibrational spectroscopic constants from PECs obtained for the HeH+ and LiH systems. The trial wave functions used are derived from the Hartree-Fock and MCSCF methods. The method used to calculate the spectroscopic constants was the Discrete Variable Representation (DVR) method. Thus, the PECs generated from the DMC produced the best results, being very close to the experimental results. Thus, the DMC method proved to be more efficient than the other methods used (MCSCF and CCSD(T)). The results obtained in this study indicate that the DMC-DVR methodology has a great potential to become a reference in the determination of spectroscopic properties.

Imaginary-Time Time-Dependent Density Functional Calculation of Excited States of Atoms Using CWDVR Approach

2021 ◽  
Vol 323 ◽  
pp. 14-20
Author(s):  
Naranchimeg Dagviikhorol ◽  
Munkhsaikhan Gonchigsuren ◽  
Lochin Khenmedekh ◽  
Namsrai Tsogbadrakh ◽  
Ochir Sukh
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Time Dependent ◽  
Discrete Variable ◽  
Coulomb Wave Function ◽  
Discrete Variable Representation ◽  
Density Functional Calculation ◽  
Imaginary Time ◽  
Sham Equation ◽  
Variable Representation

We have calculated the energies of excited states for the He, Li, and Be atoms by the time dependent self-consistent Kohn Sham equation using the Coulomb Wave Function Discrete Variable Representation CWDVR) approach. The CWDVR approach was used the uniform and optimal spatial grid discretization to the solution of the Kohn-Sham equation for the excited states of atoms. Our results suggest that the CWDVR approach is an efficient and precise solutions of excited-state energies of atoms. We have shown that the calculated electronic energies of excited states for the He, Li, and Be atoms agree with the other researcher values.

Discrete variable representation for highly excited states of hydrogen atoms in magnetic fields

1997 ◽  
Vol 56 (3) ◽  
pp. 1865-1871 ◽  
Author(s):  
Tasko Grozdanov ◽  
Lidija Andric ◽  
Corneliu Manescu ◽  
Ronald McCarroll
Keyword(s):  
Magnetic Fields ◽  
Excited States ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Hydrogen Atoms ◽  
Variable Representation

USING DISCRETE VARIABLE REPRESENTATION PATH INTEGRAL MONTE CARLO WITH METROPOLIS SAMPLING TO COMPUTE GROUND STATE WAVEFUNCTIONS

2007 ◽  
Vol 06 (02) ◽  
pp. 309-321 ◽  
Author(s):  
YINGSHENG XIAO ◽  
BILL POIRIER
Keyword(s):  
Monte Carlo ◽  
Path Integral ◽  
Ground State ◽  
Performance Enhancement ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Time Step ◽  
Path Integral Monte Carlo ◽  
Ground State Wavefunction ◽  
Variable Representation

The discrete variable representation (DVR) matrix dynamics formulation of the path integral Monte Carlo (PIMC) method, implemented numerically in a way that enables Metropolis sampling to be employed, is proposed as a means of computing ground state quantum wavefunctions. A key advantage of the DVR-PIMC approach is that customized marginal potentials may be employed, leading to significantly larger PIMC time step sizes, and substantial reductions in computational (CPU) effort. An additional key advantage of the present implementation is that the DVR provides a natural set of interpolant functions that can be used for accurate interpolation and extrapolation of function and tensor quantities away from predefined grid points. The new method is applied here to compute the ground state wavefunction of a model one degree-of-freedom (1 DOF) Morse oscillator system. A one-to-two order-of-magnitude reduction in CPU effort is observed, in comparison with a conventional PIMC simulation. The generalization for many DOFs is straightforward, and expected to result in even greater performance enhancement.

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