Nuclear quantum effects in thermal conductivity from centroid molecular dynamics
We show that the centroid molecular dynamics (CMD) method provides a realistic way to calculate the thermal diffusivity a = λ/ρcV of a quantum mechanical liquid such as para-hydrogen. Once a has been calculated, the thermal conductivity can be obtained from λ = ρcVa, where ρ is the density of the li...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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AIP Publishing
2021
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| _version_ | 1826261652016726016 |
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| author | Sutherland, BJ Moore, WHD Manolopoulos, DE |
| author_facet | Sutherland, BJ Moore, WHD Manolopoulos, DE |
| author_sort | Sutherland, BJ |
| collection | OXFORD |
| description | We show that the centroid molecular dynamics (CMD) method provides a realistic way to calculate the thermal diffusivity a = λ/ρcV of a quantum mechanical liquid such as para-hydrogen. Once a has been calculated, the thermal conductivity can be obtained from λ = ρcVa, where ρ is the density of the liquid and cV is the constant-volume heat capacity. The use of this formula requires an accurate quantum mechanical heat capacity cV, which can be obtained from a path integral molecular dynamics simulation. The thermal diffusivity can be calculated either from the decay of the equilibrium density fluctuations in the liquid or by using the Green–Kubo relation to calculate the CMD approximation to λ and then dividing this by the corresponding approximation to ρcV. We show that both approaches give the same results for liquid para-hydrogen and that these results are in good agreement with the experimental measurements of the thermal conductivity over a wide temperature range. In particular, they correctly predict a decrease in the thermal conductivity at low temperatures—an effect that stems from the decrease in the quantum mechanical heat capacity and has eluded previous para-hydrogen simulations. We also show that the method gives equally good agreement with the experimental measurements for the thermal conductivity of normal liquid helium.
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| first_indexed | 2024-03-06T19:24:44Z |
| format | Journal article |
| id | oxford-uuid:1b520a6e-122f-4237-ad41-051df409394b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:24:44Z |
| publishDate | 2021 |
| publisher | AIP Publishing |
| record_format | dspace |
| spelling | oxford-uuid:1b520a6e-122f-4237-ad41-051df409394b2022-03-26T10:59:43ZNuclear quantum effects in thermal conductivity from centroid molecular dynamicsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1b520a6e-122f-4237-ad41-051df409394bEnglishSymplectic ElementsAIP Publishing2021Sutherland, BJMoore, WHDManolopoulos, DEWe show that the centroid molecular dynamics (CMD) method provides a realistic way to calculate the thermal diffusivity a = λ/ρcV of a quantum mechanical liquid such as para-hydrogen. Once a has been calculated, the thermal conductivity can be obtained from λ = ρcVa, where ρ is the density of the liquid and cV is the constant-volume heat capacity. The use of this formula requires an accurate quantum mechanical heat capacity cV, which can be obtained from a path integral molecular dynamics simulation. The thermal diffusivity can be calculated either from the decay of the equilibrium density fluctuations in the liquid or by using the Green–Kubo relation to calculate the CMD approximation to λ and then dividing this by the corresponding approximation to ρcV. We show that both approaches give the same results for liquid para-hydrogen and that these results are in good agreement with the experimental measurements of the thermal conductivity over a wide temperature range. In particular, they correctly predict a decrease in the thermal conductivity at low temperatures—an effect that stems from the decrease in the quantum mechanical heat capacity and has eluded previous para-hydrogen simulations. We also show that the method gives equally good agreement with the experimental measurements for the thermal conductivity of normal liquid helium. |
| spellingShingle | Sutherland, BJ Moore, WHD Manolopoulos, DE Nuclear quantum effects in thermal conductivity from centroid molecular dynamics |
| title | Nuclear quantum effects in thermal conductivity from centroid molecular dynamics |
| title_full | Nuclear quantum effects in thermal conductivity from centroid molecular dynamics |
| title_fullStr | Nuclear quantum effects in thermal conductivity from centroid molecular dynamics |
| title_full_unstemmed | Nuclear quantum effects in thermal conductivity from centroid molecular dynamics |
| title_short | Nuclear quantum effects in thermal conductivity from centroid molecular dynamics |
| title_sort | nuclear quantum effects in thermal conductivity from centroid molecular dynamics |
| work_keys_str_mv | AT sutherlandbj nuclearquantumeffectsinthermalconductivityfromcentroidmoleculardynamics AT moorewhd nuclearquantumeffectsinthermalconductivityfromcentroidmoleculardynamics AT manolopoulosde nuclearquantumeffectsinthermalconductivityfromcentroidmoleculardynamics |