scholarly journals Eliminating spin contamination in auxiliary-field quantum Monte Carlo: Realistic potential energy curve of F2

2008 ◽  
Vol 128 (11) ◽  
pp. 114309 ◽  
Author(s):  
Wirawan Purwanto ◽  
W. A. Al-Saidi ◽  
Henry Krakauer ◽  
Shiwei Zhang
Keyword(s):  
Monte Carlo ◽  
Potential Energy ◽  
Quantum Monte Carlo ◽  
Potential Energy Curve ◽  
Auxiliary Field ◽  
Energy Curve ◽  
Realistic Potential ◽  
Spin Contamination

Positron and positronium chemistry by quantum Monte Carlo. V. The ground state potential energy curve of e+LiH

2000 ◽  
Vol 113 (15) ◽  
pp. 6154-6159 ◽  
Author(s):  
Massimo Mella ◽  
Gabriele Morosi ◽  
Dario Bressanini ◽  
Stefano Elli
Keyword(s):  
Monte Carlo ◽  
Potential Energy ◽  
Ground State ◽  
Quantum Monte Carlo ◽  
Potential Energy Curve ◽  
Energy Curve ◽  
Positronium Chemistry ◽  
State Potential

Quantum Monte Carlo with density matrix: potential energy curve derived properties

2017 ◽  
Vol 23 (4) ◽  
Author(s):  
Víctor S. Bonfim ◽  
Nádia M. Borges ◽  
João B. L. Martins ◽  
Ricardo Gargano ◽  
José Roberto dos S. Politi
Keyword(s):  
Monte Carlo ◽  
Potential Energy ◽  
Density Matrix ◽  
Quantum Monte Carlo ◽  
Potential Energy Curve ◽  
Energy Curve ◽  
Matrix Potential ◽  
Derived Properties

scholarly journals Erratum: “Quantum Monte Carlo calculations of the potential energy curve of the helium dimer” [J. Chem. Phys. 128, 114308 (2008)]

2010 ◽  
Vol 132 (16) ◽  
pp. 169901 ◽  
Author(s):  
R. Springall ◽  
M. C. Per ◽  
S. P. Russo ◽  
I. K. Snook
Keyword(s):  
Monte Carlo ◽  
Potential Energy ◽  
Quantum Monte Carlo ◽  
Potential Energy Curve ◽  
Chem Phys ◽  
Energy Curve ◽  
Monte Carlo Calculations

scholarly journals Quantum Monte Carlo calculated potential energy curve for the helium dimer

2010 ◽  
Vol 132 (20) ◽  
pp. 204304 ◽  
Author(s):  
Xuebin Wu ◽  
Xianru Hu ◽  
Yunchuan Dai ◽  
Chenlei Du ◽  
Shibin Chu ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Potential Energy ◽  
Quantum Monte Carlo ◽  
Potential Energy Curve ◽  
Energy Curve ◽  
Calculated Potential Energy

Quantum Monte Carlo calculations of the potential energy curve of the helium dimer

2008 ◽  
Vol 128 (11) ◽  
pp. 114308 ◽  
Author(s):  
R. Springall ◽  
M. C. Per ◽  
S. P. Russo ◽  
I. K. Snook
Keyword(s):  
Monte Carlo ◽  
Potential Energy ◽  
Quantum Monte Carlo ◽  
Potential Energy Curve ◽  
Energy Curve ◽  
Monte Carlo Calculations

scholarly journals Diffusion and Reptation Quantum Monte Carlo Study of the NaK Molecule

2018 ◽  
Author(s):  
Marc E. Segovia ◽  
Oscar Ventura
Keyword(s):  
Monte Carlo ◽  
Dipole Moment ◽  
Potential Energy ◽  
Dissociation Energy ◽  
Quantum Monte Carlo ◽  
Density Functional ◽  
Basis Set ◽  
Energy Curve ◽  
Dft Methods ◽  
Trial Wavefunction

<p>Diffusion Monte Carlo (DMC) and Reptation Monte Carlo (RMC) methods, have been applied to study some properties of the NaK molecule. Hartree-Fock (HF), Density Functional (DFT) and single and double configuration interaction (SDCI) wavefunctions with a valence quadruple zeta atomic natural orbital (VQZ/ANO) basis set were used as trial wavefunctions. Values for the potential energy curve, dissociation energy and dipole moment were calculated for all methods and compared with experimental results and previous theoretical derivations. Quantum Monte Carlo (QMC) calculations were shown to be useful methods to recover correlation in NaK, essential to obtain a reasonable description of the molecule. The equilibrium distance—interpolated from the potential energy curves—yield a value of 3.5 Å, in agreement with the experimental value. The dissociation energy, however, is not as good. In this case, a conventional CCSD(T) calculation with an extended aug-pc-4 basis set gives a much better agreement to experiment. On the contrary, the CCSD(T), other MO and DFT methods are not able to reproduce correctly the large dipole moment of this molecule. Even DMC methods with a simple HF trial wavefunction are able to give a better agreement to experiment. RMC methods are even better, and the value obtained with a B3LYP trial wavefunction is very close to the experimental one.</p>

Diffusion and Reptation Quantum Monte Carlo Study of the NaK Molecule

2018 ◽  
Author(s):  
Marc E. Segovia ◽  
Oscar Ventura
Keyword(s):  
Monte Carlo ◽  
Dipole Moment ◽  
Potential Energy ◽  
Dissociation Energy ◽  
Quantum Monte Carlo ◽  
Density Functional ◽  
Basis Set ◽  
Energy Curve ◽  
Dft Methods ◽  
Trial Wavefunction

<p>Diffusion Monte Carlo (DMC) and Reptation Monte Carlo (RMC) methods, have been applied to study some properties of the NaK molecule. Hartree-Fock (HF), Density Functional (DFT) and single and double configuration interaction (SDCI) wavefunctions with a valence quadruple zeta atomic natural orbital (VQZ/ANO) basis set were used as trial wavefunctions. Values for the potential energy curve, dissociation energy and dipole moment were calculated for all methods and compared with experimental results and previous theoretical derivations. Quantum Monte Carlo (QMC) calculations were shown to be useful methods to recover correlation in NaK, essential to obtain a reasonable description of the molecule. The equilibrium distance—interpolated from the potential energy curves—yield a value of 3.5 Å, in agreement with the experimental value. The dissociation energy, however, is not as good. In this case, a conventional CCSD(T) calculation with an extended aug-pc-4 basis set gives a much better agreement to experiment. On the contrary, the CCSD(T), other MO and DFT methods are not able to reproduce correctly the large dipole moment of this molecule. Even DMC methods with a simple HF trial wavefunction are able to give a better agreement to experiment. RMC methods are even better, and the value obtained with a B3LYP trial wavefunction is very close to the experimental one.</p>

Diffusion and Reptation Quantum Monte Carlo Study of the NaK Molecule

2018 ◽  
Author(s):  
Marc E. Segovia ◽  
Oscar Ventura
Keyword(s):  
Monte Carlo ◽  
Dipole Moment ◽  
Potential Energy ◽  
Dissociation Energy ◽  
Quantum Monte Carlo ◽  
Density Functional ◽  
Basis Set ◽  
Energy Curve ◽  
Dft Methods ◽  
Trial Wavefunction

<p>Diffusion Monte Carlo (DMC) and Reptation Monte Carlo (RMC) methods, have been applied to study some properties of the NaK molecule. Hartree-Fock (HF), Density Functional (DFT) and single and double configuration interaction (SDCI) wavefunctions with a valence quadruple zeta atomic natural orbital (VQZ/ANO) basis set were used as trial wavefunctions. Values for the potential energy curve, dissociation energy and dipole moment were calculated for all methods and compared with experimental results and previous theoretical derivations. Quantum Monte Carlo (QMC) calculations were shown to be useful methods to recover correlation in NaK, essential to obtain a reasonable description of the molecule. The equilibrium distance—interpolated from the potential energy curves—yield a value of 3.5 Å, in agreement with the experimental value. The dissociation energy, however, is not as good. In this case, a conventional CCSD(T) calculation with an extended aug-pc-4 basis set gives a much better agreement to experiment. On the contrary, the CCSD(T), other MO and DFT methods are not able to reproduce correctly the large dipole moment of this molecule. Even DMC methods with a simple HF trial wavefunction are able to give a better agreement to experiment. RMC methods are even better, and the value obtained with a B3LYP trial wavefunction is very close to the experimental one.</p>

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