Topic
Vibrational partition function
About: Vibrational partition function is a research topic. Over the lifetime, 1031 publications have been published within this topic receiving 24756 citations.
Papers published on a yearly basis
1 / 2
Papers
16 Mar 2022
Abstract: We have studied the normal modes of hydrogenated and oxidized silicon nanocrystals, namely SiH4 (silan), H2SiO (silanon), Si10H16 and Si10H14O. The small clusters (SiH4 and H2SiO) have been used for convergence tests and their bondlengths and frequencies have been compared with experimental and theoretical reference data. For the large clusters (Si10H16 and Si10H14O) we have investigated the vibrational density of states where we have identified the oxygen-related spectral features. The vibrational modes have been also analyzed with respect to the displacement patterns. The calculations have been carried out within the density-functional and density-functional perturbation theory using the local-density approximation.
TL;DR: In this article, the vibrational selfconsistent field wave function is considered as the zeroth order state in a vibrational Moller-Plesset (VMP) perturbation theory.
Abstract: The vibrational self-consistent field wave function is considered as the zeroth order state in a vibrational Moller–Plesset (VMP) perturbation theory. A method for calculating the contributions to arbitrary order is described and implemented. The theoretical background for understanding and analyzing the behavior of convergent and divergent VMP expansions is discussed briefly. Examples of convergent and divergent vibrational Moller–Plesset perturbation series are given and analyzed for two-mode model systems and for a formaldehyde quartic force field. It is found that direct use of high order VMP is problematic for calculation of anharmonic vibrational energies.
TL;DR: In this article, the high-temperature expansion coefficients to eleventh order for the partition function series for the spin-1 2 XY model on the kagome, diamond, simple cubic and hyper-trangular lattices were obtained.
TL;DR: In this paper, the construction of the molecular vibration-rotation Hamiltonian is considered, with particular reference to two alternative treatments of molecules with linear reference configurations, which can be considered to have either (i) 3N - 5 vibrational and 2 rotational degrees of freedom or (ii) 3 N - 6 vibrational, and 3 rotational degree of freedom.
Abstract: The construction of the molecular vibration-rotation Hamiltonian is considered, with particular reference to two alternative treatments of molecules with linear reference configurations. These can be considered to have either (i) 3N - 5 vibrational and 2 rotational degrees of freedom or (ii) 3N - 6 vibrational and 3 rotational degrees of freedom. In either case the classical kinetic energy consists of vibrational, rotational and translational parts given by The rotational part contains the angular velocity ω and the modified moment of inertia tensor I' of Wilson and Howard, which also occurs in the relation J α - πα = Σβ I'αβωβ involving the total (J) and vibrational (π) angular momenta. In case (i), I′ has a vanishing z row and column, where z is the axis of the molecule. This is associated with the Sayvetz condition that the total angular momentum about the axis is purely vibrational. These equations therefore contain only the two components ωx and ωy of ω, which can be eliminated to give the Hamiltonia...
TL;DR: In this paper, the authors explore the properties of the non-commutative Grassmann algebra to study the unidimensional Generalized Hubbard model, obtaining the analytical expressions for the first three terms in the high temperature expansion of its grand canonical partition function.
Abstract: We explore the properties of the non-commutative Grassmann algebra to study the unidimensional Generalized Hubbard model, obtaining the analytical expressions for the first three terms in the high temperature expansion of its grand canonical partition function, with no restrictions to the constant parameters of the model. We obtain corrections to known results, in the case of half-filled band with hopping constants t =0 and X =0.
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 1 |
| 2024 | 4 |
| 2023 | 5 |
| 2022 | 26 |
| 2021 | 10 |
| 2020 | 13 |