High Vertical Detachment Energies Research Articles

NH4+][BxH3x+1-] (x = 1-5): Role of Polynuclear Superhalogens in High-Capacity Hydrogen Storage.

Superhalogen anions are characterized by a higher vertical detachment energy (VDE) than those of halides. Ammonium borohydride, [NH4+][BH4-], is a potential candidate for high-capacity hydrogen storage but is not practically used due to its instability against dissociation to ammonia borane. Interestingly, BH4- is a superhalogen anion, and therefore, we use polynuclear BxH3x+1- superhalogen anions and study [NH4+][BxH3x+1-] complexes for x = 2-5 using density functional theory. The gravimetric hydrogen density of these complexes is smaller than that of [NH4+][BH4-] only slightly. We calculate the dehydrogenation energy and the Gibbs free energy of [NH4+][BxH3x+1-] complexes through ammonia borane. We notice that these complexes are more stable than [NH4+][BH4-], whose stability increases with an increase in x. The enhanced stability of [NH4+][BxH3x+1-] complexes appears as a consequence of the increase in the VDE of polynuclear BxH3x+1- superhalogen anions. We believe that these findings might attract experimentalists to synthesize these complexes.

Dissociative electron attachment to halogenated nucleotides: a quest for better radiosensitizers.

Tumor hypoxia hampers radiotherapy efficacy, necessitating radiosensitizers. Substituted nucleobases offer advantages as radiosensitizers. They can be incorporated into DNA with minimal gene-expression alteration, selectively targeting tumor cells and having lower toxicity to normal tissues. They possess higher electron affinity than native DNA, facilitating rapid electron attachment for cancer-cell damage. Despite advancements, exploration beyond uracil nucleobases remains limited. Herein, we investigated electron attachment to potential radiosensitizers, specifically 5-halo-2'-deoxycytidine-3'-monophosphates (5X-3'-dCMPH). Our findings indicate that 5X-3'-dCMPH nucleotides possess higher electron affinity than unsubstituted 3'-dCMPH, suggesting halogenated nucleotides are better electron acceptors. Moreover, the high vertical detachment energy (VDE) implies minimal auto-detachment, and the dissociative electron attachment (DEA) pathways suggest that dehalogenation is the favored process for halogenated systems, supported by low dissociation barriers. Notably, 5Br-3'-dCMPH and 5I-3'-dCMPH exhibit nearly barrier-free dissociation after electron attachment, and thus, they may preferentially act as superior radiosensitizers.

Colossal Stability of SiB11 (BO)12 - : An Implication as Potential Electrolyte in High-Voltage Alkali-ion Battery.

High-voltage alkali metal-ion batteries (AMIBs) require a non-hazardous, low-cost, and highly stable electrolyte with a large operating potential and rapid ion conductivity. Here, we have reported a halogen-free high-voltage electrolyte based on SiB11 (BO)12 - . Because of the weak π-orbital interaction of -BO as well as the mixed covalent and ionic interaction between SiB11 -cage and -BO ligand, SiB11 (BO)12 - has colossal stability. SiB11 (BO)12 - possesses extremely high vertical detachment energy (9.95 eV), anodic voltage limit (∼10.05 V), and electrochemical stability window (∼9.95 V). Furthermore, SiB11 (BO)12 - is thermodynamically stable at high temperatures, and its large size allows for faster cation movement. The alkali salts MSiB11 (BO)12 (M=Li, Na, and K) are easily dissociated into ionic components. Electrolytes based on SiB11 (BO)12 - greatly outperform commercial electrolytes. In short, SiB11 (BO)12 - -based compound is demonstrated to be a high-voltage electrolyte for AMIBs.

A Simple Strategy to Design Polycyclic Superhalogens.

Polycyclic hydrocarbon (PH) radicals and anions such as C9H7-, C11H7-, C13H9-, and C15H9- generally possess low electron affinity (EA) and vertical detachment energy (VDE), respectively, due to their aromaticity and, consequently, enhanced stability. In this work, we propose a simple strategy to design polycyclic superhalogens (PSs) by replacing all hydrogens by cyano (CN) groups. Superhalogens can be defined as the radicals having higher EA than halogens or anions having higher VDE than halides (3.64 eV). Our density functional calculations suggest that the EA (VDE) of PS radicals (anions) exceeds 5 eV. All these PS anions are aromatic, except C11(CN)7-, which is anti-aromatic. The superhalogen property of these PSs can be attributed to the EA of CN ligands, leading to the delocalization of extra electronic charge significantly as explained using prototype C5H5-x(CN)x systems. We also notice that the 'superhalogenity' (superhalogen behavior) of C5H5-x(CN)x- is directly related to their aromaticity. We have also shown that the substitution of CN is energetically favorable, which confirms their experimental viability. Our findings should motivate experimentalists to synthesize these superhalogens for further exploration and future applications.

CF4-n (SO3) n (n = 1–4): a new series of organic superhalogens

Superhalogens are species having higher electron affinity (EA) or vertical detachment energy (VDE) than those of halogen atoms. CF4 is a molecule having no positive EA or VDE. In the quest for new organic superhalogens, we substitute SO3 in the place of F in CF4 successively and study the resulting CF4-n (SO3) n (n = 1–4) neutral molecules and their anions using density functional theory and quantum theory of atoms in molecule at the ωB97xD/6-311 + G(d) and B3LYP/6-311 + G(d) levels, respectively. The EA of CF4-n (SO3) n and VDE of their anions, being greater than 5 eV, suggest that all these molecules behave as superhalogens. There is significant structural relaxation in C(SO3)4 molecule, leading to the remarkably high VDE of corresponding anions. The superhalogen properties have been explained on the basis of the electronic charge delocalisation over SO3 moieties. We believe that these findings will add a new chapter in the exploration of organic superhalogens.

M(BO)k+1- Anions: Novel Superhalogens Based on Boronyl Ligands.

Superhalogens have been a subject of continuous attraction in the last four decades due to their unusual structures and interesting applications. In the quest for new superhalogens based on boronyl (BO) ligands, we investigate M(BO)k+1- anions using a high-level ab initio CCSD(T) and B3LYP density functional method for M = Li, Na, K, Be, Mg, Ca, B, and Al. Their structures are linear for M = Li, Na, K; trigonal planar for M = Be, Mg, Ca; and tetrahedral for M = B, Al. These anions are energetically and thermodynamically stable against various fragmentations. Their superhalogen property has been established due to their higher vertical detachment energy (VDE) than halogen, being in the range 4.44-7.81 eV. For a given k, the stability and VDE of M(BO)k+1- anions decrease with an increase in the size of M, which is due to the decrease in charge delocalization on BO moieties. There exists a linear correlation between frontier orbitals energy gap and VDE with coefficient R2 = 0.93888. It was also noticed that the BO ligand, due to the lower dimerization energy, can be preferably used as an inorganic analogue of CN. However, the structural relaxation in BO-based neutral species significantly affect the VDE and, hence, their superhalogen nature. We believe that these findings should be interesting for researchers working in superatomic chemistry as well as in boron chemistry.

Be2H3L2− (L=CH3 and F–I): Hyperhalogen anions with ultrashort beryllium-beryllium distances

The superalkali cations and superhalogen anions commonly have different type of core moieties. Based on the previous reports that Be2H3L′2+ (L′=NH3 and noble gases Ne–Xe) are superalkali cations, in the present work, we designed the superhalogen anions Be2H3L2− (L=CH3 and halogens F–I), and both superalkali cations and superhalgen anions can be constructed using Be2H3 as the core moiety. The newly designed Be2H3L2− species are much more stable than their isoelectronic cationic counterparts Be2H3L′2+, as can be reflected by the highly exergonic substitution reaction of L′ ligand in Be2H3L′2+ with isoelectronic L− to give Be2H3L2−. These anionic species possess the well-defined electronic structure, which can be proven by their large HO-MO–LUMO gaps of 4.69 eV to 5.38 eV. It is remarkable that Be2H3L2− can be regarded as the hyperhalogen anions due to the extremely high vertical detachment energies (5.38 eV to 6.06 eV) and the Be–Be distances in these species (1.776 Å to 1.826 Å) are short in ultrashort metal-metal distances (defined as dM–M<1.900 Å) between main group metals. In the designed five small model species, three of them, i.e. Be2H3L2− (L=CH3, Cl, and Br), are kinetical viable global energy minima, which are the promising target for generation and characterization in anion photoelectron spectroscopy. The analogue molecule [t-Bu–Be2H3–t-Bu]− with bulky protecting tert-butyl (t-Bu) groups is designed as a possible target for synthesis and isolation in condensed states.

Density Functional Theory Study of Ultrashort Metal−Metal Distances in Diberyllium Complexes Bearing Carbene Ligands

AbstractDiberyllium complexes with ultrashort metal−metal distances (USMMDs, defined as dM−M<1.900 Å) are fascinating for the nature of the valence electronic structure of Be atoms. In this paper a family of diberyllium complexes [L−BeH3Be−L]+ (1–7), in which L was an N‐heterocyclic carbene (NHC) or a mesoionic carbene (MIC), were studied by Density Functional Theory (DFT) at the B3LYP/cc‐pVTZ level. It was found that complexes 1–7 possessed ultrashort Be−Be distances of 1.754 Å–1.779 Å and strong covalent bonds between a Be atom and its adjacent carbene center (Ccarb) at once. Electronic structures and chemical bonding analyses ascribed USMMDs between the Be atoms to the Be−H−Be three‐center two‐electron (3c‐2e) bonds. The strong Be−Ccarb bonds were determined by combining effects of covalent interaction and electrostatic interaction between the Be and the Ccarb atoms. These complexes exhibited a great stability with large highest occupied molecular orbital‐lowest unoccupied molecular orbital (HOMO‐LUMO) gaps, high vertical detachment energies (VDEs) and low vertical electron affinities (VEAs) and are potential targets in future experiments.

Comprehensive DFT calculations on protonated metallic hexa halide anions [formula omitted](M=Ni, Pd, Pt; X=F, Cl)

We propose a new series of superacids by protonation of hexa-halide anions MX6−(M ​= ​Ni, Pd, Pt & X ​= ​F, Cl) by using combination of DFT/B3LYP method and SDD basis set. The strength of superacid is calculated by their Gibbs free energies of deprotonation. The acidity of these superacids is not only related to electronic stability of corresponding metallic anions MX6− but also on topology of protonated metallic anions. We have noticed that these base anions have very high vertical detachment energy (VDE), which indicates that they belong to superhalogenic family. A rough correlation (R2 ​= ​0.62) is found in between VDE of MX6−and acidity of protonatedMX6−. The AIM analyses of HMX6 help to understand its superacidic behaviour. Some electronic parameters of HMX6 are also calculated by using same level theory. We have also discussed the optimized structure of NiF6Li supersalt. The HOMO LUMO plots are used to describe chemical reactivity as well as the binding nature of HMX6 superacids and LiNiF6 salt.

Superatomic Signature and Reactivity of Silver Clusters with Oxygen: Double Magic Ag 17 – with Geometric and Electronic Shell Closure

Understanding the stability and reactivity of silver clusters toward oxygen provides insights to design new materials of coinage metals with atomic precision. Herein, we report a systematic study o...

Deltahedral Organo-Zintl Superhalogens.

Zintl ions constitute a special type of naked anionic clusters, mainly consisting of Group 13, 14, and 15 elements of the Periodic Table. Due to the presence of multiple negative ions, the chemistry of Zintl ions is unique. They not only form Zintl phases with alkali and alkaline-earth metal cations, but also form organo-Zintl clusters with distinct properties. By first-principles calculations based on density functional theory, we have designed a new deltahedral organo-Zintl cluster with Ge94- as the core and aromatic heterocyclic compounds as ligands. Calculations on such complexes show that they form a special class of system known as a superhalogen (SH), with a high vertical detachment energy of 4.9 eV. The density of states (DOS), partial DOS, and different molecular orbitals give additional information about the bonding features of the complexes.

Prediction of the Iron-Based Polynuclear Magnetic Superhalogens with Pseudohalogen CN as Ligands.

To explore stable polynuclear magnetic superhalogens, we perform an unbiased structure search for polynuclear iron-based systems based on pseudohalogen ligand CN using the CALYPSO method in conjunction with density functional theory. The superhalogen properties, magnetic properties, and thermodynamic stabilities of neutral and anionic Fe2(CN)5 and Fe3(CN)7 clusters are investigated. The results show that both of the clusters have superhalogen properties due to their electron affinities (EAs) and that vertical detachment energies (VDEs) are significantly larger than those of the chlorine element and their ligand CN. The distribution of the extra electron analysis indicates that the extra electron is aggregated mainly into pseudohalogen ligand CN units in Fe2(CN)5¯ and Fe3(CN)7¯ cluster. These features contribute significantly to their high EA and VDE. Besides superhalogen properties, these two anionic clusters carry a large magnetic moment just like the Fe2F5¯ cluster. Additionally, the thermodynamic stabilities are also discussed by calculating the energy required to fragment the cluster into various smaller stable clusters. It is found that Fe(CN)2 is the most favorable fragmentation product for anionic Fe2(CN)5¯ and Fe3(CN)7¯ clusters, and both of the anions are less stable against ejection of Fe atoms than Fe(CN)n-x.

Star-like superalkali cations featuring planar pentacoordinate carbon.

Superalkali cations, known to possess low vertical electron affinities (VEAs), high vertical detachment energies, and large highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps, are intriguing chemical species. Thermodynamically, such species need to be the global minima in order to serve as the promising targets for experimental realization. In this work, we propose the strategies of polyhalogenation and polyalkalination for designing the superalkali cations. By applying these strategies, the local-minimum planar pentacoordinate carbon (ppC) cluster CBe5 can be modified to form a series of star-like superalkali ppC or quasi-ppC CBe5X5 (+) (X = F, Cl, Br, Li, Na, K) cations containing a CBe5 moiety. Polyhalogenation and polyalkalination on the CBe5 unit may help eliminate the high reactivity of bare CBe5 molecule by covering the reactive Be atoms with noble halogen anions and alkali cations. Computational exploration of the potential energy surfaces reveals that the star-like ppC or quasi-ppC CBe5X5 (+) (X = F, Cl, Br, Li, Na, K) clusters are the true global minima of the systems. The predicted VEAs for CBe5X5 (+) range from 3.01 to 3.71 eV for X = F, Cl, Br and 2.12-2.51 eV for X = Li, Na, K, being below the lower bound of the atomic ionization potential of 3.89 eV in the periodic table. Large HOMO-LUMO energy gaps are also revealed for the species: 10.76-11.07 eV for X = F, Cl, Br and 4.99-6.91 eV for X = Li, Na, K. These designer clusters represent the first series of superalkali cations with a ppC center. Bonding analyses show five Be-X-Be three-center two-electron (3c-2e) σ bonds for the peripheral bonding, whereas the central C atom is associated with one 6c-2e π bond and three 6c-2e σ bonds, rendering (π and σ) double aromaticity. Born-Oppenheimer molecular dynamics simulations indicate that the CBe5 motif is robust in the clusters. As planar hypercoordination carbon species are often thermodynamically unstable and highly reactive, the superalkali cation characters of these ppC species should be highlighted, which may be suitable for experimental realization.

Structures and electron affinity of XO30,−, XOF40,− and XO2F20,− (X = P, As, Sb, Bi): a theoretical study of novel superhalogen formulae and exceptions of superhalogen formulae

Most superhalogen species are in the form of oxides or halides. To enrich the family of superhalogen species, herein, we investigated the structures and electron affinity (EA) values of higher group 15 elements (X = P, As, Sb, Bi) oxyfluoride species XO30,−, XOF40,− and XO2F20,−, at the CCSD(T)/aug-cc-pVTZ-pp & aug-cc-pVTZ //B3LYP/aug-cc-pVTZ-pp & aug-cc-pVTZ levels (aug-cc-pVTZ-pp for X = Sb and Bi). Some oxyfluoride species, i.e., PO2F20,−, AsO2F20,−, SbO2F20,−, POF40,−, AsOF40,−, SbOF40,− and BiOF40,−, were found to possess higher EA (VDE: 5.0–6.2 eV; ADE: 4.5–5.5 eV) than halogens (F: 3.4 eV; Cl: 3.6 eV). Thus, we recommended that the oxyfluorides in the form of XO2F20,− and XOF40,− should be considered as potential superhalogens, which have not been considered previously. Surprisingly, we showed that BiO3 and BiO2F2, in superhalogen formulae, possess a high vertical detachment energy (VDE) yet a low adiabatic detachment energy (ADE). This is in marked contrast to the previously reported superhalogens, which generally contain both the high VDE and high ADE values. It is the first report about exceptions of superhalogen formulae. These findings revealed that for the analogous main-group compounds with the same structural formula, the difference in the metallic property of the core element could lead to the significant difference in the ground structures of either the anionic or neutral structures, which would result in the much differed superhalogen features.

Sequential Observation of Alkali-halide Gas Phase Clusters in High Resolution TOF-MS and Prediction of Their Structures

Alkali halide clusters are interesting model systems that can provide information about how crystal properties evolve. To study these properties, a high-resolution atmospheric pressure inlet time-of-flight mass spectrometry (APi-TOF-MS) study of the sequential sodium halides series, Cl− (NaCl)n and Br− (NaBr)m, has been reported, and the viability of the APi-TOF-MS equipped with an electrospray ionization source in determining cluster compositions has been demonstrated. The isotopic patterns were well resolved, as n=4 and 7 were determined to be the magic numbers for Cl− (NaCl)n clusters, which were particularly abundant in the mass spectra. A global minimum search based on density functional theory enabled basin hopping yield the most stable structures for the mentioned series. The structures exhibit several distinct motifs which can be roughly categorized as linear chain, rock salt, and hexagonal ring. This work provides an effective way to discover and elucidate the nonstoichiometry sodium halide clusters. These clusters possess very high vertical detachment energies and are generally called as superhalogens, which play important roles in chemistry because they are widely used in the synthesis of new classes of charge-transfer salts.

Photoelectron spectroscopy and theoretical study of M(IO3)2− (M = H, Li, Na, K): Structural evolution, optical isomers, and hyperhalogen behavior

H(IO3)2(-) and M(IO3)2(-) (M = Li, Na, K) anions were successfully produced via electrospray ionization of their corresponding bulk salt solutions, and were characterized by combining negative ion photoelectron spectroscopy and quantum chemical calculations. The experimental vertical detachment energies (VDEs) of M(IO3)2(-) (M = H, Li, Na, K) are 6.25, 6.57, 6.60, and 6.51 eV, respectively, and they are much higher than that of IO3(-) (4.77 eV). The theoretical calculations show that each of these anions has two energetically degenerate optical isomers. It is found that the structure of H(IO3)2(-) can be written as IO3(-)(HIO3), in which the H atom is tightly bound to one of the IO3(-) groups and forms an iodic acid (HIO3) molecule; while the structures of M(IO3)2(-) can be written as (IO3(-))M(+)(IO3(-)), in which the alkali metal atoms interact with the two IO3(-) groups almost equally and bridge the two IO3(-) groups via two O atoms of each IO3(-) with the two MOOI planes nearly perpendicular to each other. In addition, the high VDEs of M(IO3)2(-) (M = Li, Na, K) can be explained by the hyperhalogen behavior of their neutral counterparts.

Structure and properties of Mn4Cl9: An antiferromagnetic binary hyperhalogen

Calculations based on density functional theory show that the structure of Mn(4)Cl(9) anion is that of a Mn atom at the core surrounded by three MnCl(3) moieties. Since Mn is predominantly divalent and MnCl(3) is known to be a superhalogen with a vertical detachment energy (VDE) of 5.27 eV, Mn(4)Cl(9) can be viewed as a hyperhalogen with the formula unit Mn(MnCl(3))(3). Indeed, the calculated VDE of Mn(4)Cl(9) anion, namely 6.76 eV, is larger than that of MnCl(3) anion. More importantly, unlike previously discovered hyperhalogens, Mn(4)Cl(9) is the first such hyperhalogen species composed of only two constituent atoms. We further show that Mn(4)Cl(9) can be used as a ligand to design molecules with even higher VDEs. For example, Li[Mn(MnCl(3))(3)](2) anion has a VDE of 7.26 eV. These negatively charged clusters are antiferromagnetic with most of the magnetic moments localized at the Mn sites. Our studies show new pathways for creating binary hyperhalogens.

Electronic structure and reactivity of a biradical cluster: Sc3O6−

The Sc(3)O(6)(-) cluster anions were produced by laser ablation and studied by reaction with n-butane in a fast flow reactor and by photoelectron spectroscopy. The reactivity experiments indicated that one Sc(3)O(6)(-) cluster can activate two n-butane molecules consecutively with rate constants on the order of 10(-10) cm(3) molecule(-1) s(-1) under near room-temperature conditions, suggesting that the even-electron system Sc(3)O(6)(-) has a highly reactive electronic structure. The photoelectron spectroscopy determined a high vertical detachment energy (VDE) of 5.63 ± 0.08 eV for the Sc(3)O(6)(-) cluster. Density functional computations indicated that the lowest energy isomer of Sc(3)O(6)(-) is an oxygen-centered biradical with a high VDE and is highly reactive toward n-butane, which is in good agreement with the experiments. The Sc(3)O(6)(-) cluster may serve as an ideal model system to provide insight into the real-life chemistry involved with the coupled O(-)˙···O(-)˙ dimers over the surfaces of metal oxide catalysts.

Electron attachment to DNA single strands: gas phase and aqueous solution

The 2′-deoxyguanosine-3′,5′-diphosphate, 2′-deoxyadenosine-3′,5′-diphosphate, 2′-deoxycytidine-3′,5′-diphosphate and 2′-deoxythymidine-3′,5′-diphosphate systems are the smallest units of a DNA single strand. Exploring these comprehensive subunits with reliable density functional methods enables one to approach reasonable predictions of the properties of DNA single strands. With these models, DNA single strands are found to have a strong tendency to capture low-energy electrons. The vertical attachment energies (VEAs) predicted for 3′,5′-dTDP (0.17 eV) and 3′,5′-dGDP (0.14 eV) indicate that both the thymine-rich and the guanine-rich DNA single strands have the ability to capture electrons. The adiabatic electron affinities (AEAs) of the nucleotides considered here range from 0.22 to 0.52 eV and follow the order 3′,5′-dTDP > 3′,5′-dCDP > 3′,5′-dGDP > 3′,5′-dADP. A substantial increase in the AEA is observed compared to that of the corresponding nucleic acid bases and the corresponding nucleosides. Furthermore, aqueous solution simulations dramatically increase the electron attracting properties of the DNA single strands. The present investigation illustrates that in the gas phase, the excess electron is situated both on the nucleobase and on the phosphate moiety for DNA single strands. However, the distribution of the extra negative charge is uneven. The attached electron favors the base moiety for the pyrimidine, while it prefers the 3′-phosphate subunit for the purine DNA single strands. In contrast, the attached electron is tightly bound to the base fragment for the cytidine, thymidine and adenosine nucleotides, while it almost exclusively resides in the vicinity of the 3′-phosphate group for the guanosine nucleotides due to the solvent effects. The comparatively low vertical detachment energies (VDEs) predicted for 3′,5′-dADP− (0.26 eV) and 3′,5′-dGDP− (0.32 eV) indicate that electron detachment might compete with reactions having high activation barriers such as glycosidic bond breakage. However, the radical anions of the pyrimidine nucleotides with high VDE are expected to be electronically stable. Thus the base-centered radical anions of the pyrimidine nucleotides might be the possible intermediates for DNA single-strand breakage.

Electron solvation in water-ammonia mixed clusters: Structure, energetics, and the nature of localization states of the excess electron

The structure and energetics of water-ammonia mixed clusters with an excess electron, [(H2O)n(NH3)m]- with m=1, n=2-6 and m=2, n=2, and also the corresponding neutral clusters are investigated in detail by means of ab initio quantum chemical calculations. The authors focus on the localization structure of the excess electron with respect to its surface versus interiorlike states, its binding to ammonia versus water molecules, the spatial and orientational arrangement of solvent molecules around the excess electron, the changes of the overall hydrogen-bonded structure of the clusters as compared to those of the neutral ones and associated dipole moment changes, vertical detachment energies of the anionic clusters, and also the vertical attachment energies of the neutral clusters. It is found that the hydrogen-bonded structure of the anionic clusters are very different from those of the neutral clusters unlike the case of water-ammonia dimer anion, and these changes in structural arrangements lead to drastically different dipole moments of the anionic and the neutral clusters. The spatial distribution of the singly occupied molecular orbital holding the excess electron shows only surface states for the smaller clusters. However, for n=5 and 6, both surface and interiorlike binding states are found to exist for the excess electron. For the surface states, the excess electron can be bound to the dangling hydrogens of either an ammonia or a water molecule with different degrees of stability and vertical detachment energies. The interiorlike states, wherever they exist, are found to have a higher vertical detachment energy than any of the surface states of the same cluster. Also, for interiorlike states, the ammonia molecule with its dangling hydrogens is always found to stay on top or on a far side of the charge density of the excess electron without participating in the hydrogen bond network of the cluster; the intermolecular hydrogen bonds are formed by the water molecules only which add to the overall stability of these anionic clusters.