| Records |
| Author |
Ancilotto, F.; Barranco, M.; Navarro, J.; Pi, M. |
Title  |
A Density Functional Approach to Para-hydrogen at Zero Temperature |
Type |
Journal Article |
| Year |
2016 |
Publication |
Journal of Low Temperature Physics |
Abbreviated Journal |
J. Low Temp. Phys. |
| Volume |
185 |
Issue |
1-2 |
Pages |
26-38 |
| Keywords |
Solid and liquid bulk para-hydrogen; Small para-hydrogen clusters; Density functional theory |
| Abstract |
We have developed a density functional (DF) built so as to reproduce either the metastable liquid or the solid equation of state of bulk para-hydrogen, as derived from quantum Monte Carlo zero temperature calculations. As an application, we have used it to study the structure and energetics of small para-hydrogen clusters made of up to molecules. We compare our results for liquid clusters with diffusion Monte Carlo (DMC) calculations and find a fair agreement between them. In particular, the transition found within DMC between hollow-core structures for small N values and center-filled structures at higher N values is reproduced. The present DF approach yields results for (pH) clusters indicating that for small N values a liquid-like character of the clusters prevails, while solid-like clusters are instead energetically favored for . |
| Address |
[Ancilotto, Francesco] Dipartimento Fis & Astron Galileo Galilei, Padua, Italy, Email: manuel@ecm.ub.edu |
| Corporate Author |
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Thesis |
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| Publisher |
Springer/Plenum Publishers |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0022-2291 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000382142000003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2814 |
| Permanent link to this record |
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| Author |
Ancilotto, F.; Barranco, M.; Navarro, J.; Pi, M. |
| Title |
Cavitation of electron bubbles in liquid parahydrogen |
Type |
Journal Article |
| Year |
2011 |
Publication |
Molecular Physics |
Abbreviated Journal |
Mol. Phys. |
| Volume |
109 |
Issue |
23-24 |
Pages |
2757-2762 |
| Keywords |
liquid parahydrogen; electron bubbles; density functional theory; capillary approximation |
| Abstract |
Within a finite-temperature density functional approach, we have investigated the structure of electron bubbles in liquid parahydrogen below the saturated vapour pressure, determining the critical pressure at which electron bubbles explode as a function of temperature. The electron-parahydrogen interaction has been modelled by a Hartree-type local potential fitted to the experimental value of the conduction band-edge for a delocalized electron in pH(2). We have found that the pressure for bubble explosion is, in absolute value, about a factor of two smaller than that of the homogeneous cavitation pressure in the liquid. Comparison with the results obtained within the capillary model shows the limitations of this approximation, especially as temperature increases. |
| Address |
[Barranco, Manuel; Pi, Marti] Univ Barcelona, Fac Fis, Dept ECM, E-08028 Barcelona, Spain, Email: manuel@ecm.ub.es |
| Corporate Author |
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Thesis |
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| Publisher |
Taylor & Francis Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0026-8976 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000299109300007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
930 |
| Permanent link to this record |
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| Author |
Mateo, D.; Barranco, M.; Navarro, J. |
| Title |
Elementary excitations in superfluid He-3-He-4 mixtures |
Type |
Journal Article |
| Year |
2010 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys. Rev. B |
| Volume |
82 |
Issue |
13 |
Pages |
134529 - 13pp |
| Keywords |
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| Abstract |
We have studied the dynamic structure function of superfluid He-3-He-4 mixtures at zero temperature as a function of pressure and He-3 concentration. Results obtained in the full random-phase approximation (RPA) plus density-functional theory and in a generalized Landau-Pomeranchuk approach are presented and compared with experiment. Analytic expressions for several sum rules of the dynamic structure functions have been determined, and have been used to obtain average energies of the collective excitations. In the RPA approach, the dispersion relation of the collective modes shows typical features of level repulsion between zero-soundlike and phonon-rotonlike excitations. The structure of the coupled RPA equations for the mixture leads in a natural way to the hybridization of the collective modes. The mixed He-3-He-4 dynamic structure function quenches the zero-soundlike mode before it crosses the phonon-roton branch, causing that the former mode only appears with enough strength after the crossing. |
| Address |
[Mateo, David; Barranco, Manuel] Univ Barcelona, Fac Fis, Dept ECM, E-08028 Barcelona, Spain |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1098-0121 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
ISI:000283291200005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
354 |
| Permanent link to this record |
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| Author |
Navarro, J.; Mateo, D.; Barranco, M.; Sarsa, A. |
| Title |
Mg impurity in helium droplets |
Type |
Journal Article |
| Year |
2012 |
Publication |
Journal of Chemical Physics |
Abbreviated Journal |
J. Chem. Phys. |
| Volume |
136 |
Issue |
5 |
Pages |
054301 - 9pp |
| Keywords |
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| Abstract |
Within the diffusion Monte Carlo approach, we have determined the structure of isotopically pure and mixed helium droplets doped with one magnesium atom. For pure He-4 clusters, our results confirm those of Mella et al. [J. Chem. Phys. 123, 054328 (2005)1 that the impurity experiences a transition from a surface to a bulk location as the number of helium atoms in the droplet increases. Contrarily, for pure He-3 clusters Mg resides in the bulk of the droplet due to the smaller surface tension of this isotope. Results for mixed droplets are presented. We have also obtained the absorption spectrum of Mg around the 3s3p P-1(1) <- 3s(2) S-1(0) transition. |
| Address |
[Sarsa, A.] Univ Cordoba, Dept Fis, Fac Ciencias, E-14071 Cordoba, Spain, Email: fa1sarua@uco.es |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Inst Physics |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0021-9606 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000300547200018 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
921 |
| Permanent link to this record |
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| Author |
Pi, M.; Barranco, M.; Navarro, J.; Ancilotto, F. |
| Title |
Nucleation and cavitation in parahydrogen |
Type |
Journal Article |
| Year |
2012 |
Publication |
Chemical Physics |
Abbreviated Journal |
Chem. Phys. |
| Volume |
399 |
Issue |
|
Pages |
213-217 |
| Keywords |
Nucleation; Cavitation; Metastable phases; Liquid parahydrogen |
| Abstract |
We have used a density functional approach to investigate thermal homogeneous nucleation and cavitation in parahydrogen. The effect of electrons as seeds of heterogeneous cavitation in liquid parahydrogen is also discussed within the capillary model. |
| Address |
[Pi, Marti; Barranco, Manuel] Univ Barcelona, Fac Fis, Dept ECM, E-08028 Barcelona, Spain, Email: marti@ecm.ub.es |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0301-0104 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000304196100027 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1039 |
| Permanent link to this record |
