1
|
Prosmiti R, González-Lezana T. Computational Modeling: Up-to-Date Approaches and Cutting-Edge Applications from Clusters, Nanostructures to Bulk Systems. Chemphyschem 2024:e202400207. [PMID: 38837591 DOI: 10.1002/cphc.202400207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Indexed: 06/07/2024]
Abstract
The contributions in this special theme collection, in honor to Prof. P. Villarreal, cover a broad variety of computational methodologies and experimental techniques, containing studies on gas phase, clusters and condensed phase systems.
Collapse
Affiliation(s)
- Rita Prosmiti
- Instituto de Fìsica Fundamental, IFF-CSIC, Serrano 123, 28006, Madrid, Spain
| | | |
Collapse
|
2
|
Alharzali N, Rodríguez-Segundo R, Prosmiti R. Modelling interactions of cationic dimers in He droplets: microsolvation trends in He nK 2+ clusters. Phys Chem Chem Phys 2021; 23:7849-7859. [PMID: 33220666 DOI: 10.1039/d0cp05406b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the results of a detailed theoretical investigation of small K2+-doped He clusters. The structural characteristics and stabilities of such cations are determined from ab initio electronic structure calculations at the MRCI+Q level of theory. The underlying interactions show a multireference character and such effects are analyzed. The interaction potentials are constructed employing an interpolation technique within the inverse problem theory method, while the nuclear quantum effects are computed for the trimers, their spatial arrangements are discussed, and information was extracted on the orientational anisotropy of the forces. We found that energetically the most stable conformer corresponds to linear arrangements that are taking place under large amplitude vibrations, with high zero-point energy. We have further looked into the behavior of higher-order species with various He atoms surrounding the cationic dopant. By using a sum of potentials approach and an evolutionary programming method, we analyzed the structural stability of clusters with up to six He atoms in comparison with interactions energies obtained from MRCI+Q quantum chemistry computations. Structures containing Hen motifs that characterize pure rare gas clusters, appear for the larger K2+-doped He clusters, showing selective growth during the microsolvation process of the alkali-dimer cation surrounded by He atoms. Such results indicate the existence of local solvation microstructures in these aggregates, where the cationic impurity could get trapped for a short time, contributing to the slow ionic mobility observed experimentally in ultra-cold He-droplets.
Collapse
Affiliation(s)
- Nissrin Alharzali
- Institute of Fundamental Physics (IFF-CSIC), CSIC, Serrano 123, 28006 Madrid, Spain.
| | | | | |
Collapse
|
3
|
Valdés Á, Prosmiti R. Quantum effects on the stability of the He 5 I 2 van der Waals conformers. J Comput Chem 2019; 40:2200-2206. [PMID: 31148224 DOI: 10.1002/jcc.25870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/10/2019] [Accepted: 05/16/2019] [Indexed: 11/05/2022]
Abstract
We present 15-dimensional quantum multiconfiguration time-dependent Hartree calculations of the vibrational levels of the He5 I2 van der Waals (vdW) complex employing an ab initio-based potential energy surface (PES). The energies and spatial features of such bound structures are analyzed, providing predictions on the structures and relative stabilities of its three lowest isomers. We found that the most stable isomer corresponds to all five He atoms encircling the I2 molecule, indicating that in this case the anharmonic quantum effects do not stabilize the isomers involving a He atom in a linear configuration as reported previously for the smaller HeN I2 systems. Such finding provides information on the overall structuring of the finite-size-solvent systems, highlighting the intriguing interplay between weak intermolecular interactions and quantum effects. © 2019 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Álvaro Valdés
- Departamento de Física, Universidad Nacional de Colombia, Calle 26, Cra 39, Edificio 404, Bogotá, Colombia
| | - Rita Prosmiti
- Departamento PAMS, Instituto de Física Fundamental (IFF-CSIC), CSIC, Serrano 123, 28006, Madrid, Spain
| |
Collapse
|
4
|
Valdés Á, Prosmiti R, Villarreal P, Delgado-Barrio G. Theoretical investigation of the He4Br2 conformers. J Phys Chem A 2012; 116:7169-76. [PMID: 22667396 DOI: 10.1021/jp3026682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Full dimensional quantum dynamics calculations of the three lowest isomers of the He(4)Br(2) van der Waals molecule in its ground electronic state are reported. The calculations are performed using the multiconfiguration time-dependent Hartree (MCTDH) method and a realistic potential form that includes the sum of three body ab initio coupled-cluster single double triple [CCSD(T)] He-Br(2) interactions plus the He-He and Br-Br interactions. This potential exhibits several multiple minima, with the three lowest ones lying very close in energy, just within 2 cm(-1). Such small differences are also found in the calculated binding energies of the three most stable conformers, indicating the floppiness of the system and, thus, the need of accurate potential forms and quantum full dynamics methods to treat this kind of complexes. The 12 dimensional results reported in this work present benchmark data and, thus, can serve to evaluate approximate methods aiming to describe higher order rare gas-dihalogen (N > 4) complexes. A comparison with previous studies using different potential forms and approaches to the energetics for the He(4)Br(2) cluster is also presented.
Collapse
Affiliation(s)
- Álvaro Valdés
- Instituto de Física Fundamental (IFF-CSIC), CSIC, Serrano 123, 28006 Madrid, Spain.
| | | | | | | |
Collapse
|
5
|
Structure and dynamics of noble gas-halogen and noble gas ionic clusters: When theory meets experiment. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.05.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
6
|
Rodríguez-Cantano R, López-Durán D, González-Lezana T, Delgado-Barrio G, Villarreal P, Yurtsever E, Gianturco FA. Spin-polarized Rb2 interacting with bosonic He atoms: potential energy surface and quantum structures of small clusters. J Phys Chem A 2012; 116:2394-404. [PMID: 22320704 DOI: 10.1021/jp3004932] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A new full-dimension potential energy surface of the three-body He-Rb₂(³Σ(u)(+)) complex and a quantum study of small (⁴He)(N)-Rb₂(³Σ(u)(+)) clusters, 1 ≤ N ≤ 4, are presented. We have accurately fitted the ab initio points of the interaction to an analytical form and addressed the dopant's vibration, which is found to be negligible. A Variational approach and a Diffusion Monte Carlo technique have been applied to yield energy and geometric properties of the selected species. Our quantum structure calculations show a transition in the arrangements of the helium atoms from N = 2, where they tend to be separated across the diatomic bond, to N = 4, in which a closer packing of the rare gas particles is reached, guided by the dominance of the He-He potential over the weaker interaction of the latter adatoms with the doping dimer. The deepest well of the He-Rb₂ interaction is placed at the T-shape configuration, a feature which causes the dopant to be located as parallel to the helium "minidroplet". Our results are shown to agree with previous findings on this and on similar systems.
Collapse
|
7
|
Valdés A, Prosmiti R, Villarreal P, Delgado-Barrio G. Full-dimensional multi configuration time dependent Hartree calculations of the ground and vibrationally excited states of He2,3Br2 clusters. J Chem Phys 2011; 135:054303. [PMID: 21823696 DOI: 10.1063/1.3618727] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Quantum dynamics calculations are reported for the tetra-, and penta-atomic van der Waals He(N)Br(2) complexes using the multiconfiguration time-dependent Hartree (MCTDH) method. The computations are carried out in satellite coordinates, and the kinetic energy operator in this set of coordinates is given. A scheme for the representation of the potential energy surface based on the sum of the three-body HeBr(2) interactions at CSSD(T) level plus the He-He interaction is employed. The potential surfaces show multiple close lying minima, and a quantum description of such highly floppy multiminima systems is presented. Benchmark, full-dimensional converged results on ground vibrational/zero-point energies are reported and compared with recent experimental data available for all these complexes, as well as with previous variational quantum calculations for the smaller HeBr(2) and He(2)Br(2) complexes on the same surface. Some low-lying vibrationally excited eigenstates are also computed by block improved relaxation calculations. The binding energies and the corresponding vibrationally averaged structures are determined for different conformers of these complexes. Their relative stability is discussed, and contributes to evaluate the importance of the multiple-minima topology of the underlying potential surface.
Collapse
Affiliation(s)
- Alvaro Valdés
- Instituto de Física Fundamental (IFF-CSIC), CSIC, Madrid, Spain.
| | | | | | | |
Collapse
|
8
|
Pérez de Tudela R, López-Durán D, González-Lezana T, Delgado-Barrio G, Villarreal P, Gianturco FA, Yurtsever E. Quantum features of a barely bound molecular dopant: Cs2(3Σu) in bosonic helium droplets of variable size. J Phys Chem A 2011; 115:6892-902. [PMID: 21585200 DOI: 10.1021/jp111825n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present in this work the study of small (4)He(N)-Cs(2)((3)Σ(u)) aggregates (2 ≤ N ≤ 30) through combined variational, diffusion Monte Carlo (DMC), and path integral Monte Carlo (PIMC) calculations. The full surface is modeled as an addition of He-Cs(2) interactions and He-He potentials. Given the negligible strength and large range of the He-Cs(2) interaction as compared with the one for He-He, a propensity of the helium atoms to pack themselves together, leaving outside the molecular dopant is to be expected. DMC calculations determine the onset of helium gathering at N = 3. To analyze energetic and structural properties as a function of N, PIMC calculations with no bosonic exchange, i.e., Boltzmann statistics, at low temperatures are carried out. At T = 0.1 K, although acceptable one-particle He-Cs(2) distributions are obtained, two-particle He-He distributions are not well described, indicating that the proper symmetry should be taken into account. PIMC distributions at T = 1 K already compare well with DMC ones and show minor exchange effects, although binding energies are still far from having converged in terms of the number of quantum beads. As N increases, the He-He PIMC pair correlation function shows a clear tendency to coincide with the experimental boson-liquid helium one at that temperature. It supports the picture of a helium droplet which carries the molecular impurity on its surface, as found earlier for other triplet dimers.
Collapse
|
9
|
Prosmiti R, Delgado-Barrio G, Villarreal P, Yurtsever E, Coccia E, Gianturco FA. Structuring a Quantum Solvent around a Weakly Bound Dopant: The He−Cs2(3Σu) Complex. J Phys Chem A 2009; 113:14718-29. [DOI: 10.1021/jp9048583] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - Ersin Yurtsever
- Department of Chemistry, Koç University, Rumeligeneri Yolu, 34450 Sariyer, Istanbul, Turkey
| | | | | |
Collapse
|
10
|
de Lara-Castells MP, Villarreal P, Delgado-Barrio G, Mitrushchenkov AO. An optimized full-configuration-interaction nuclear orbital approach to a “hard-core” interaction problem: Application to ([sup 3]He)[sub N]–Cl[sub 2](B) clusters (N≤4). J Chem Phys 2009; 131:194101. [DOI: 10.1063/1.3263016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
11
|
de Lara-Castells MP, Delgado-Barrio G, Villarreal P, Mitrushchenkov AO. A full-configuration interaction “nuclear orbital” method to study doped HeN3 clusters (N⩽4). J Chem Phys 2006; 125:221101. [PMID: 17176126 DOI: 10.1063/1.2403846] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
An efficient full configuration interaction (FCI) treatment, based on the Jacobi-Davidson algorithm, is developed in order to study small doped (3)He(N) clusters. The state of each He atom in a given cluster is described by a set of wave-functions which by extention of the quantum-chemistry notation are caller here "nuclear orbitals". The FCI treatment is applied to the calculation of binding energies and helium natural orbitals of (3)He(N)...Br(2)(X) complexes. In agreement with our previous calculations using a Hartree-Fock approach [Phys. Rev. Lett. 93, 053401 (2004)], in which the He-He interaction is modified at small distances to account for short-range correlation effects, the lowest-energy states of each multiplet are found to be very close in energy. The natural orbital analysis, in turn, indicates the adequacy of the "nuclear orbital" approach in these systems.
Collapse
Affiliation(s)
- M P de Lara-Castells
- Instituto de Matemáticas y Física Fundamental (C.S.I.C.), Serrano 123, E-28006 Madrid, Spain.
| | | | | | | |
Collapse
|