Zobrazeno 1 - 10
of 386
pro vyhledávání: '"Savin, Andreas"'
Autor:
Scemama, Anthony, Savin, Andreas
Short-range corrections to long-range selected configuration interaction calculations are derived from perturbation theory considerations and applied to harmonium (with two to six electrons for some low-lying states). No fitting to reference data is
Externí odkaz:
http://arxiv.org/abs/2407.09151
Autor:
Scemama, Anthony, Savin, Andreas
The expectation value of the Hamiltonian using a model wave function is widely used to estimate the eigenvalues of electronic Hamiltonians. We explore here a modified formula for models based on long-range interaction. It scales differently the singl
Externí odkaz:
http://arxiv.org/abs/2405.12618
Autor:
Scemama, Anthony, Savin, Andreas
In this article, we explore the construction of Hamiltonians with long-range interactions and their corrections using the short-range behavior of the wave function. A key aspect of our investigation is the examination of the one-particle potential, k
Externí odkaz:
http://arxiv.org/abs/2404.19405
Autor:
Savin, Andreas, Karwowski, Jacek
Publikováno v:
Journal of Chemical Physics, 2023, 159 (13), pp.134107
The adiabatic connection formalism, usually based on the first-order perturbation theory, has been generalized to an arbitrary order. The generalization stems from the observation that the formalism can be derived from a properly arranged Taylor expa
Externí odkaz:
http://arxiv.org/abs/2310.11073
Autor:
Karwowski, Jacek, Savin, Andreas
Publikováno v:
In: Grabowski, I., S{\l}owik, K., Maruani, J., Br\"andas, E.J. (eds) Advances in Methods and Applications of Quantum Systems in Chemistry, Physics, and Biology. Progress in Theoretical Chemistry and Physics, 34, 60 (2024) Springer, Cham
Properties of erfonium, a Hooke atom with the Coulomb interaction potential $1/r$ replaced by a non-singular $\text{erf}(\mu r)/r$ potential are investigated. The structure of the Hooke atom potential and properties of its energy spectrum, relative t
Externí odkaz:
http://arxiv.org/abs/2308.12717
Autor:
Savin, Andreas, Karwowski, Jacek
Sources of energy errors resulting from the replacement of the physical Coulomb interaction by its long-range $\mathrm{erfc}(\mu r)/r$ approximation are explored. It is demonstrated that the results can be dramatically improved and the range of $\mu$
Externí odkaz:
http://arxiv.org/abs/2301.12308
Autor:
Scemama, Anthony, Savin, Andreas
We like to attribute a number of electrons to spatial domains (atoms, bonds, ...). However, as a rule, the number of electrons in a spatial domain is not a sharp number. We thus study probabilities for having any number of electrons (between 0 and th
Externí odkaz:
http://arxiv.org/abs/2205.09365
Autor:
Karwowski, Jacek, Savin, Andreas
The notion of the n-th order local energy, generated by the n-th power of the Hamiltonian, has been introduced. The n-th order two-particle coalescence conditions have been derived from the requirements that the n-th order local energy at the coalesc
Externí odkaz:
http://arxiv.org/abs/2204.09897
Autor:
Scemama, Anthony, Savin, Andreas
Probabilities to find a chosen number of electrons in flexible domains of space are calculated for highly correlated wave functions. Quantum mechanics can produce higher probabilities for chemically relevant arrangements of electrons in these regions
Externí odkaz:
http://arxiv.org/abs/2203.08640
The Kohn-Sham method uses a single model system, and corrects it by a density functional the exact user friendly expression of which is not known and is replaced by an approximated, usable, model. We propose to use instead more than one model system,
Externí odkaz:
http://arxiv.org/abs/2112.13139