First-principles calculations of gold and silver clusters doped with lithium atoms

Accepted Manuscript First-principles calculations of gold and silver clusters doped with lithium atoms Ramón A. Alvarez B, N.S. Flores-Lopez, G. Calderón-Ayala, R. Britto Hurtado, M. Cortez-Valadez, M. Flores-Acosta PII:

S1386-9477(18)30852-X

DOI:

https://doi.org/10.1016/j.physe.2018.12.014

Reference:

PHYSE 13402

To appear in:

Physica E: Low-dimensional Systems and Nanostructures

Received Date: 7 June 2018 Revised Date:

8 December 2018

Accepted Date: 12 December 2018

Please cite this article as: Ramó.A. Alvarez B, N.S. Flores-Lopez, G. Calderón-Ayala, R.B. Hurtado, M. Cortez-Valadez, M. Flores-Acosta, First-principles calculations of gold and silver clusters doped with lithium atoms, Physica E: Low-dimensional Systems and Nanostructures (2019), doi: https:// doi.org/10.1016/j.physe.2018.12.014. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT

First-principles calculations of Gold and Silver clusters doped with Lithium atoms 1

2

1

1

2*

Ramón A. Alvarez B. , NS Flores-Lopez , G. Calderón-Ayala , R. Britto Hurtado , M. Cortez-Valadez , M. FloresAcosta

1†

1

México 2

RI PT

Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190 Hermosillo, Sonora,

Universidad Estatal de Sonora. Rosales No. 189 Col. Centro C.P. 83100, Tel (662)6890100 Hermosillo, México 3

CONACYT - Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190,

M AN U

Abstract

SC

Hermosillo, Sonora, México

This study focuses on bimetallic clusters of Aun-1Lix, Agn-1Lix for (n=2-19, x=1,2) optimized with the computational Gaussian 09 package using the Ab initio calculations and the density functional theory (DFT) with the hybrid functional B3LYP and the basis set LanL2DZ. The paper presents the calculations of the following stability parameters: vertical ionization potential (VIP), vertical electron affinity (VEA), chemical hardness,

TE D

chemical potential, second energy difference, the difference between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). An odd-even oscillation tendency was observed. The hardness of the gold clusters increased when they were doped with a single Li atom. The hardness of the

EP

gold clusters doped with two Li atoms increased significantly for clusters Au2Li2, Au3Li2, Au6Li and Au7Li2, Ag2Li2, Ag4Li2, Ag6Li2 and Ag16Li2. Other Magic Number Clusters were

AC C

identified.

Keywords: Au clusters doped with Li atoms; Ag clusters doped with Li atoms; DFT calculations; Electronic stability parameters. Corresponding Author: Tel.: +52 662 2893792. *e-mail address: [email protected] (M. Cortez-Valadez) † e-mail address: [email protected] (M. Flores-Acosta)

ACCEPTED MANUSCRIPT

1. Introduction

RI PT

The computational calculations of the molecular structures allow us to predict whether certain atomic structures exist, and to establish experimental methods to synthesize and characterize the atomic arrangement obtained theoretically. Over the past decade the theoretical and experimental investigation of metallic and ionic clusters has been proved

SC

relevant in the analysis of their properties, such as [1-2] electronic [3-4], optical [5], magnetic [6] and their stability. The physical and chemical properties that the materials

M AN U

show at nanometric scale are different in comparison to those shown by bulk material [5, 7], therefore, the theoretical and experimental study of these small new materials are attractive for future technological applications. For instance, clusters of 2 to 13 rhenium atoms supported in graphene [8], gold clusters with less than 30 atoms supported on a carbon film [9], cluster Au20 with a structural arrangement similar to bulk gold obtained on carbon film [10]. These small structures can be observed through a High-Angle

13].

TE D

Annular Dark Field-Scanning Transmission Electron Microscopy (HAADF-STEM) [11-

Furthermore, the study of doped clusters is notable for the search of new and stable structures [14] that can optimize the individual properties of pure material. For instance,

EP

clusters of AgnCo improve the catalytic properties of the pure metal Ag [15], clusters of Ag54 doped with Pd improve the adsorption of C2H2 and C2H4 given that H2 cannot bond

AC C

in any area of the pure silver cluster [16]. One study reports that the magnetism of ionic clusters increases up to 4 times in comparison with the neutral clusters for one structure of Ag54 doped with Cu+1 [17]. Doping with alkaline atoms improves properties such as: stability [14], electronic [18], optical nonlinearity [19] and the extraction of new magical clusters [20]. In the particular case of lithium, Krishnakanta Mondal et al. report that Au19Li shows an improved energy absorption of CO in comparison with the cluster of pure Au20 [21]. Maryam Yousofizadeh et al. report boron clusters doped with one lithium atom are more stable thermodynamically, which improves the first hyperpolarizabilities [22]. Therefore, this study reports for the first time an analysis of the structural

ACCEPTED MANUSCRIPT

properties of clusters Aun-xLix, Agn-xLix for (n=2-19 x=1,2) focusing on the geometrical configuration, vertical electron affinity (VEA), vertical ionization potential (VIP), second energy difference and the energy difference between HOMO-LUMO. The may predict

optical, magnetic applications, among others.

2. Computational Methodology

RI PT

the properties of bimetallic nanostructures and also facilitate the study of catalytic,

The clusters were designed with the graphical interface GausView, using DFT with the

SC

hybrid functional B3LYP (3-parameter, Lee-Yang-Parr) in combination with the basis set LANL2DZ (Los Alamos National Laboratory and double-zeta). Initially, the Au and Ag

M AN U

clusters with a stable minimal configuration reported in the literature were considered [23-27]. Afterwards, the structures were doped and doubly doped with the Li atom to perform the optimization and frequency calculations to guarantee that the structure is a local minimum. Analyzing the stationary points in the potential energy surface and detecting only positive frequencies, guaranteeing that the optimized cluster is a structure with a local minimum, and consequently, the ionic and cationic energies were

3. Results

TE D

calculated.

EP

3.1 Molecular structures

AC C

Figures 1 and 2 show gold and silver clusters doped with lithium, respectively, which correspond to low energy clusters and guarantee one local minimum. It can be observed in the figure that Au clusters doped with Li made of less than 9 atoms show a flat configuration, and clusters made of 10 and 18 atoms show a cage structure with the Li atom inside the cage. In the second doping (2 Li atoms) when the clusters Au7Li and Au8Li were reconfigured to the clusters Au6Li2 and Au7Li2 the flat configuration changes into a three-dimensional configuration. The clusters made of 10 to 14 atoms change to a cage configuration, however the atom is no longer inside of the structure.

ACCEPTED MANUSCRIPT

The silver clusters made of less than 6 atoms doped with a single Li atom, show a flat configuration; whereas the clusters made of more than 7 atoms have a threedimensional configuration, resulting in cage clusters Ag14Li, Ag15Li, Ag16Li and Ag17Li changes into a three-dimensional configuration.

RI PT

with one Li atom in the center of the cage. During the second doping the cluster Ag5Li

approximation and the basis set LANL2DZ.

SC

Figure 1. Clusters Aun-1Li and Aun-1Li2(n=2-20) modelled with DFT with the B3LYP

Figure 2. Clusters Agn-1Li and Agn-1Li2(n=2-20) modelled with DFT with the B3LYP

M AN U

approximation and the basis set LANL2DZ

3.2 Vertical Electron Affinity and Vertical Ionization Potential

The vertical electron affinity (VEA) reflects the binding energy of one neutral cluster that obtains one electron. VEA is defined as the difference between the energy of the neutral

TE D

optimized structure and the energy of the optimized anionic structure. The vertical electron affinity calculations (VEA) and the vertical ionization potential (VIP) are parameters used for the characterization of the stability of a cluster. The parameters of the clusters AunLi, AunLi2, AgnLi and AgnLi2 were calculated using the following

EP

equations [28-29].

(1)


 = | + 1 − |

(2)

AC C


 = | −  − 1|

Where E(N) is the neutral energy of the cluster, E(N-1) is the energy that corresponds to the anion state of the geometry of the neutral cluster and E(N+1) is the energy that corresponds to the cation state of the geometry of the neutral cluster.

ACCEPTED MANUSCRIPT

Figure 3a shows the increase of the VEA energy at the same time that the size of the clusters increases. The VEA obtained for cluster Ag19Li is 2.292 eV, which is similar to the result obtained by Ghanty K. et al [30] who report a value of 2.451 eV using the computation package Amsterdam Density Functional (ADF2006). On the other hand,

RI PT

Chunmei T. [31] obtained a VEA for the cluster Au17Li=2.37 eV using the program DMol under the DFT/PBE. We obtained a similar result for Au17Li 2.49eV. The VEA of Ag clusters doped with Li decreased with respect to the pure Ag cluster. The cases Ag3=2.1eV, Ag7=1.8eV, Ag9=2.2eV, Ag13=2,4eV, Ag18=2.3eV and Ag20=1.9eV [32]

SC

decreased the most in VIP passing to Ag2Li=1.08eV, Ag6Li=1.48eV, Ag8Li=1.54eV, Ag12Li=2.08eV, Ag17Li=1.97eV and Ag19Li=1.61eV. Cluster AgLi2 has a negative value,

M AN U

this shows that when the cluster receives an electron it becomes less stable. After double doping the cluster with Li the electron affinity decreases in the doped clusters, except for Ag15Li2 and Ag9Li2.

Figure 3. Size dependency of (a) Vertical Electron Affinity (VEA), (b) Ionization potential,

TE D

for clusters Aun-1Lix and Agn-1Lix(n=2-20, x=1,2)

VIP is a parameter commonly used to determine the stability of clusters. This is related to the bond energy of one cluster in neutral state that loses one electron. VIP is defined as the difference between the energy of the optimized cationic structure and the energy

EP

of the optimized neutral structure. Figure 3b shows the odd-even pattern of the VIP, where the even cluster shows a higher value than the odd neighbors. Similar results are

AC C

obtained when the results of the doping are compared with the results obtained by Jinlan Wang et al., in the study of the electronic and structural properties for clusters Aun(n=2-20) [27]. The VIP decreases after doping a pure cluster with lithium atoms. After the second doping the VIP decreases again, when comparing the results with the pure cluster and the doped cluster, the cluster AuLi2 decreased the most. The VIP for cluster Au7=7.30eV increased after doping and doubly doping the cluster with lithium Au6Li=7.50eV and Au5Li2=7.59eV. In a similar way the VIP for Au13=6.98 eV increased its VIP Au12Li=7.12 and Au11Li2=7.02eV. The results of the silver clusters doping were similar to experimental work of C. Jackschath et al [33]. The doping decreased the VIP.

ACCEPTED MANUSCRIPT

The VIP of cluster AgLi2 decreased the most. On the other hand, the higher VIP values correspond to structures Au5Li=8.37eV and Ag4Li2=6.89eV. The VIP for cluster Ag4 is 6.43 [34], after doping this cluster with Li the VIP improved

RI PT

with Ag3Li=6.50eV and Ag2Li2=6.63eV. Similarly, when comparing the results obtained by Huda and Ray [35] an improvement is observed, who report a VIP for Ag6=6.25eV, Ag7=5.12eV, Ag8=6.09eV and Ag9=4.35. When these clusters were doped with one single Li atom we obtained a higher VIP of 6.74, 5.41, 6.32, 5.17 eV, respectively. Silver

SC

clusters with two Li atoms obtained values of 6.89, 5.37, 6.37, 5.19 eV. In this way a higher VIP was obtained when compared with the values of pure Ag cluster. The

M AN U

clusters Ag12=6.04eV, Ag14=6.07eV and Ag16=5.84eV [36] doped with Li increased its VIP with Ag11Li=6.09eV, Ag13Li=6.09, and Ag15Li=6.09 changed to 5.84eV a 6.09eV. 3.3 Chemical hardness (η)

Hardness is one of the global descriptors that measures the resistance of the molecular system to the deformation of its electron cloud or the resistance of the system to charge

TE D

transference, for a system of N-electrons the (η) is defined as the second derivative of the energy with respect to N [37].  

  

=   = 



  

(3)

EP

  

For the constant external potential (V) due to the fixed nuclei, (E) the total electron energy of the system and (N) the number of electrons, the calculations of the hardness

AC C

were performed through the approximation of the finite differences using the following equation:

=

 

(4)

ACCEPTED MANUSCRIPT

Figure 4. Dependency on the size of the chemical hardness for clusters Aun-1Lix and Agn-1Lix(n=2-20, x=1,2) An odd-even rotation in the chemical hardness values is shows in Figure 4. The

RI PT

systems of the open shell are treated with the default unrestricted spin. For the even clusters we used RB3LYP with singlet multiplicity, and for odd clusters we used UB3LYP (the wave function of the non-restricted open layer) doublet multiplicity. The electronic deformation for even clusters was more difficult. The double doping increased

SC

the hardness of doped gold clusters Au2Li2, Au3Li2, Au6Li2 and Au7Li2 and of silver clusters Ag2Li2, Ag4Li2, Ag6Li2 and Ag16Li2. The hardness decreased for clusters AuLi2,

M AN U

Au16Li2 and Au18Li2, and Ag8Li2.

The hardness of gold clusters [26] Au4=2.80, Au6=2.79, Au7=2.06, Au10=2.15, Au12=1.92 increase when doped with a single Li atom. The clusters that show the highest increase are Au3Li=3.15eV, Au2Li2=3.74eV, Au5Li= 3.31eV, Au4Li2=3.29eV.

TE D

3.4 Chemical potential

The chemical potential measures the escaping tendency of the electrons from the balance system in a way that the electrons flow from regions with high chemical potential to regions with low chemical potential. The calculations of the chemical



AC C

=−

EP

potential were calculated with the following equation:



(5)

Figure 5. Chemical potential for clusters Aun-1Lix and Agn-1Lix(n=2-20, x=1,2) Figure 5 shows the values of the chemical potential which obtained a higher chemical potential after double doping Au with Li atoms; the cluster AuLi2 had the highest chemical potential. Similarly, doubly doped clusters Ag have a higher chemical potential being AgLi2 the one with the highest chemical potential.

ACCEPTED MANUSCRIPT

3.5 Second difference of energy HOMO-LUMO The second energy difference reflects the relative stability of the clusters between neighbors. This generating a zig-zag graph where the maxima are known as “Magic

with Li was calculated with the following equation: ! "# 

=   ! "#  +   ! "#  − 2 ! "# ! "#  =   ! "#  +   ! "#  − 2 ! "# 

(6) (7)

SC

∆   ∆  

RI PT

number clusters”. The second energy difference for doped and doubly doped clusters

M AN U

The values of the second energy difference in figure 6a show how Au clusters doubly doped with Li have a higher energy in comparison with the clusters doped with a single atom. It can be observed that even clusters have a higher second energy difference in comparison with odd clusters. The higher values of ∆2E are found in clusters AunLi2 for n=2, 4, 8, 10, 12, 14, 16 and AunLi for n=3, 5, 17. Clusters AunLi show an odd-even alternation of n=2-7, however in n=8-10 the alternation is lost and continues in n>11.

TE D

For cluster AunLi2 the alternation is odd and even with the exception of Au7Li2. Ag clusters doped with Li show an odd-even oscillation from a cluster with 6 atoms. The following clusters obtained a higher energy difference in comparison with the rest of the clusters Ag3Li, Au2Li2, Au16Li, Au15Li2, Ag12Li, Ag2Li2, Ag15Li2. In most of the cases the

EP

even clusters are higher than their odd neighbors, with the exception of Ag3Li2, which is

AC C

the only odd cluster with a second energy difference higher than an even cluster.

Figure 6. a) Second energy difference b) gap difference of HOMO-LUMO for clusters Aun-1Lix and Agn-1Lix(n=2-20, x=1,2) The gap between HOMO and LUMO is shown in figure 6b, which shows an even oscillation approximation. In clusters with less than 7 atoms the second doping of Au significantly increases the gap. The clusters with higher gap difference are Au2Li2, Au3Li2 and Au4Li2 with one gap of 4.36 eV, 3.86 eV and 3.29 eV, respectively. A significant difference between the doping and double doping of clusters between 8 and

ACCEPTED MANUSCRIPT

15 atoms was not found. Clusters with more than 16 atoms, this is doped clusters Au16Li, Au17Li and Au19Li, have a higher gap than doubly doped clusters. The opposite happens for clusters with n<8, where the gap decreased after the second doping. For Ag clusters the structures Ag2Li2, Ag3Li2, Ag6Li2, Ag11Li2, Ag14Li2, Ag15Li2, Ag16Li2

RI PT

increased the gap, whereas for structures AgLi2, Ag8Li2, Ag10Li2 it decreased. Conclusions

Clusters from Au and Ag doped with Lin (n=1, 2) are studied for the first time, using the

SC

density functional theory and the hybrid functional B3LYP and the basis LANL2DZ. We found that VIP, VEA, the hardness and the second energy difference show an odd-even

M AN U

alternation behavior. The results show a good agreement with the results reported by other authors. The analysis showed that the most stable structures are AunLi2 for (n=2, 4, 10, 12, 14, 16), AgnLi for (n=11, 13, 15 y 17); and AgnLi2 for (n=4, 10, 12, 14, 16). The results show that clusters Au10Li2, Au17Li, Ag4Li2 y Ag5Li correspond to “magic number clusters” when they present a higher stability, according to the stability parameters considered in this study.

TE D

The results obtained in this study may favor the detection of small structures of AuLi obtained by diverse types of synthesis, when comparing structural parameters. Additionally, this study may complement a previous analysis of the adsorption and interaction of AuLi and AgLi nanostructures on nanostructured materials such as:

EP

graphene, carbon nanotubes, fullerene and several types of laminar structures.

AC C

Acknowledgments.

The computational resources for this investigation was facilitated by UNISON/Acarus. We appreciate the support given by PRODEP through C.A. UNISON-CA-188 project. References

[1] Baletto, F., & Ferrando, R. (2005). Structural properties of nanoclusters: Energetic, thermodynamic, and kinetic effects. Reviews of modern physics, 77(1), 371. [2] Martins, J. L., Buttet, J., & Car, R. (1985). Electronic and structural properties of sodium clusters. Physical Review B, 31(4), 1804.

ACCEPTED MANUSCRIPT

[3] Borsella, E., Cattaruzza, E., De Marchi, G., Gonella, F., Mattei, G., Mazzoldi, P., & Polloni, R. (1999). Synthesis of silver clusters in silica-based glasses for optoelectronics applications. Journal of non-crystalline solids, 245(1-3), 122-128.

RI PT

[4] Li, X. B., Wang, H. Y., Yang, X. D., Zhu, Z. H., & Tang, Y. J. (2007). Size dependence of the structures and energetic and electronic properties of gold clusters. The Journal of chemical physics, 126(8), 084505.

SC

[5] Menard, L. D., Gao, S. P., Xu, H., Twesten, R. D., Harper, A. S., Song, Y., ... & Nuzzo, R. G. (2006). Sub-nanometer Au monolayer-protected clusters exhibiting molecule-like electronic behavior: quantitative high-angle annular dark-field scanning transmission electron microscopy and electrochemical characterization of clusters with precise atomic stoichiometry. The Journal of Physical Chemistry B, 110(26), 12874-12883.

M AN U

[6] Li, X., Kiran, B., Cui, L. F., & Wang, L. S. (2005). Magnetic properties in transitionmetal-doped gold clusters: M@ Au 6 (M= Ti, V, Cr). Physical review letters, 95(25), 253401. [7] Johnston, R. L. (2002). Atomic and molecular clusters. CRC Press. [8] Miramontes, O., Bonafé, F., Santiago, U., Larios-Rodriguez, E., Velázquez-Salazar, J. J., Mariscal, M. M., & Yacaman, M. J. (2015). Ultra-small rhenium clusters supported on graphene. Physical Chemistry Chemical Physics, 17(12), 7898-7906.

TE D

[9] Li, J., Yin, D., Chen, C., Li, Q., Lin, L., Sun, R., & Wang, Z. (2015). Atomic-scale observation of dynamical fluctuation and three-dimensional structure of gold clusters. Journal of Applied Physics, 117(8), 085303.

EP

[10] Wang, ZW y RE Palmer. "Imágenes atómicas directas y fluctuaciones dinámicas del clúster tetraédrico Au 20". Nanoscale 4.16 (2012): 4947-4949.

AC C

[11] Li, Junjie, et al. "Observación a escala atómica de la migración y coalescencia de au nanoclusters en la superficie YSZ mediante STEM corregido por aberración". Informes científicos 4 (2014): 5521. [12] Nishijima, M., Hiraga, K., Yamasaki, M., & Kawamura, Y. (2006). Characterization of β′ phase precipitates in an Mg-5 at% Gd alloy aged in a peak hardness condition, studied by high-angle annular detector dark-field scanning transmission electron microscopy. Materials transactions, 47(8), 2109-2112. [13] Pizarro, J., Galindo, P. L., Guerrero, E., Yáñez, A., Guerrero, M. P., Rosenauer, A., & Molina, S. I. (2008). Simulation of high angle annular dark field scanning transmission electron microscopy images of large nanostructures. Applied Physics Letters, 93(15), 153107.

ACCEPTED MANUSCRIPT

[14] Lu, Q. L., Jalbout, A. F., Luo, Q. Q., Wan, J. G., & Wang, G. H. (2008). Theoretical study of hydrogenated Mg, Ca@ Al 12 clusters. The Journal of chemical physics, 128(22), 224707.

RI PT

[15] Rodríguez-Kessler, P. L., & Rodríguez-Domínguez, A. R. (2015). Structural, electronic, and magnetic properties of AgnCo (n= 1–9) clusters: A first-principles study. Computational and Theoretical Chemistry, 1066, 55-61 [16] Liu, D. (2016). DFT study of selective hydrogenation of acetylene to ethylene on Pd doping Ag nanoclusters. Applied Surface Science, 386, 125-137.

SC

[17] Li, W., & Chen, F. (2014). Effect of Cu-doped site and charge on the optical and magnetic properties of 55-atom Ag cluster: A density functional theory study. Computational Materials Science, 81, 587-594

M AN U

[18] Otero, N., Van Alsenoy, C., Karamanis, P., & Pouchan, C. (2013). Electric response properties of neutral and charged Al13X (X= Li, Na, K) magic clusters. A comprehensive ab initio and density functional comparative study. Computational and Theoretical Chemistry, 1021, 114-123. [19] Iqbal, J., & Ayub, K. (2016). Enhanced electronic and non-linear optical properties of alkali metal (Li, Na, K) doped boron nitride nano-cages. Journal of Alloys and Compounds, 687, 976-983.

TE D

[20] Tang, C., Zhu, W., Zhang, K., He, X., & Zhu, F. (2014). The density functional studies of the doped gold cages Au17M (M= Cu, Ag, Li, Na, K). Computational and Theoretical Chemistry, 1049, 62-66.

EP

[21] Mondal, K., Manna, D., Ghanty, T. K., & Banerjee, A. (2014). Significant modulation of CO adsorption on bimetallic Au19Li cluster. Chemical Physics, 428, 75-81.

AC C

[22] Yousofizadeh, M., Shakerzadeh, E., & Bamdad, M. (2017). Electronic and nonlinear optical characteristics of the LiBn (n= 4–11) nanoclusters: A theoretical study. Microelectronic Engineering, 183, 64-68.

[23] Chen, M., Dyer, J. E., Li, K., & Dixon, D. A. (2013). Prediction of structures and atomization energies of small silver clusters,(Ag) n, n< 100. The Journal of Physical Chemistry A, 117(34), 8298-8313. [24] Fournier, R. (2001). Theoretical study of the structure of silver clusters. The Journal of chemical physics, 115(5), 2165-2177.

ACCEPTED MANUSCRIPT

[25] Zhao, J., Luo, Y., & Wang, G. (2001). Tight-binding study of structural and electronic properties of silver clusters. The European Physical Journal D-Atomic, Molecular, Optical and Plasma Physics, 14(3), 309-316.

RI PT

[26] Deka, A., & Deka, R. C. (2008). Structural and electronic properties of stable Aun (n= 2–13) clusters: a density functional study. Journal of Molecular Structure: THEOCHEM, 870(1-3), 83-93. [27] Wang, J., Wang, G., & Zhao, J. (2002). Density-functional study of Au n (n= 2–2 0) clusters: Lowest-energy structures and electronic properties. Physical Review B, 66(3), 035418.

SC

[28] Sun, J., Xie, X., Cao, B., & Duan, H. (2017). A density-functional theory study of Au13, Pt13, Au12Pt and Pt12Au clusters. Computational and Theoretical Chemistry, 1107, 127-135.

M AN U

[29] Toprek, D., & Koteski, V. (2016). Ab initio calculations of the structure, energetics and stability of AunTi (n= 1–32) clusters. Computational and Theoretical Chemistry, 1081, 9-17. [30] Ghanty, T. K., Banerjee, A., & Chakrabarti, A. (2009). Structures and the Electronic Properties of Au19X Clusters (X= Li, Na, K, Rb, Cs, Cu, and Ag). The Journal of Physical Chemistry C, 114(1), 20-27.

TE D

[31] Tang, C., Zhu, W., Zhang, K., He, X., & Zhu, F. (2014). The density functional studies of the doped gold cages Au17M (M= Cu, Ag, Li, Na, K). Computational and Theoretical Chemistry, 1049, 62-66.

EP

[32] Tian, D., Zhang, H., & Zhao, J. (2007). Structure and structural evolution of Agn (n= 3–22) clusters using a genetic algorithm and density functional theory method. Solid State Communications, 144(3-4), 174-179.

AC C

[33] Jackschath, C., Rabin, I., & Schulze, W. (1992). Electron impact ionization of silver clusters Ag n, n≦ 36. Zeitschrift für Physik D Atoms, Molecules and Clusters, 22(2), 517-520. [34] Matulis, V. E., Ivashkevich, O. A., & Gurin, V. S. (2003). DFT study of electronic structure and geometry of neutral and anionic silver clusters. Journal of Molecular Structure: THEOCHEM, 664, 291-308. [35] Huda, M. N., & Ray, A. K. (2003). Electronic structures and magic numbers of small silver clusters: A many-body perturbation-theoretic study. Physical Review A, 67(1), 013201.

ACCEPTED MANUSCRIPT

[36] Liao, M. S., Watts, J. D., & Huang, M. J. (2014). Theoretical Comparative Study of Oxygen Adsorption on Neutral and Anionic Ag n and Au n Clusters (n= 2–25). The Journal of Physical Chemistry C, 118(38), 21911-21927.

AC C

EP

TE D

M AN U

SC

RI PT

[37] Pearson, R. G. (2005). Chemical hardness and density functional theory. Journal of Chemical Sciences, 117(5), 369-377.

ACCEPTED MANUSCRIPT

RI PT

Aun-1Li

Au2Li

Au3Li

Au4Li

Au5Li

Au6Li

Au7Li

Au8Li

Au9Li

Au10Li

Au11Li

Au12Li

Au13Li

Au16Li Aun-1Li2

Au17Li

SC

AuLi

M AN U

Au14Li

TE D

Au18Li

Au15Li

Au19Li

Au2Li2

Au3Li2

Au4Li2

Au5Li2

Au6Li2

Au7Li2

Au8Li2

Au9Li2

Au10Li2

Au14Li2

Au15Li2

AC C

EP

AuLi2

Au11Li2

Au12Li2

Au13Li2

Au16Li2

Au17Li2

Au18Li2

Figure 1/6 Ramón A. Alvarez B. et al.

ACCEPTED MANUSCRIPT

Agn-1Li

Ag2Li

Ag3Li

Ag4Li

Ag6Li

Ag7Li

Ag8Li

Ag9Li

Ag11Li

Ag12Li

Ag13Li

Ag16Li Agn-1Li2

Ag17Li

SC

M AN U

Ag15Li

TE D

Ag18Li

Ag19Li

Ag2Li2

Ag3Li2

Ag4Li2

Ag5Li2

Ag7Li2

Ag8Li2

Ag9Li2

Ag10Li2

Ag14Li2

Ag15Li2

AC C

Ag6Li2

Ag14Li

Ag10Li

EP

AgLi2

Ag5Li

RI PT

AgLi

Ag11Li2

Ag12Li2

Ag13Li2

Ag16Li2

Ag17Li2

Ag18Li2

Figure 2/6 Ramón A. Alvarez B. et al.

ACCEPTED MANUSCRIPT

b)

RI PT

a)

8.5 Aun-1Li

4

Au n-1Li

Aun-2Li2

Au n-2Li2

8.0

3

2

1

Ag n-1Li

0

7.5

Ag n-2Li2

7.0 6.5 6.0 5.5 5.0

2

4

6

8

10

12

14

16

18

20

22

24

Cluster size (n)

4.5

26

0

2

4

6

8

10

12

14

16

M AN U

0

SC

Agn-2Li2

Ionization potential (eV)

Electronic Afinity (eV)

Agn-1Li

18

Clusters size (n)

AC C

EP

TE D

Figure 3/6 Ramón A. Alvarez B. et al.

20

22

24

26

ACCEPTED MANUSCRIPT

4.0 Aun-1Li Aun-2Li2 Agn-1Li

RI PT

Agn-2Li2

3.0

2.5

2.0

SC

Chemical Hardness (eV)

3.5

0

2

4

6

M AN U

1.5

8

10

12

14

16

18

cluster size (n)

AC C

EP

TE D

Figure 4/6 Ramón A. Alvarez B. et al.

20

22

ACCEPTED MANUSCRIPT

RI PT

-2.0 Aun-1Li

-2.5

Aun-2Li2 Agn-2Li2

SC

-3.5 -4.0 -4.5 -5.0 -5.5 0

2

4

6

M AN U

Chemical potential (eV)

Agn-1Li

-3.0

8

10

12

14

16

18

TE D

Cluster size (n)

AC C

EP

Figure 5/6 Ramón A. Alvarez B. et al.

20

22

ACCEPTED MANUSCRIPT

b)

RI PT

a)

4.5

Aun-1Li

Aun-1Li

Aun-2Li2

Aun-2Li2

4.0

Agn-1Li

4

Agn-1Li

2

0

-2

Agn-2Li2

3.5 3.0 2.5

SC

HOMO-LUMO (eV)

2

∆ E(n) (eV)

Agn-2Li2

2.0 1.5

-4

6

8

10

12

14

16

18

Cluster size (n)

20

M AN U

1.0 4

2

4

6

8

10

12

Cluster size (n)

AC C

EP

TE D

Figure 6/6 Ramón A. Alvarez B. et al.

14

16

18

20

ACCEPTED MANUSCRIPT

Electronic properties of Au and Ag doped cluster with Li Atoms > DFT calculations>

AC C

EP

TE D

M AN U

SC

RI PT

Theoretical study of metallic clusters with Li atoms.