ORIGINAL PAPER Zintl superalkalis as building blocks of supersalts G. Naaresh Reddy 1 & A. Vijay Kumar 1,2 & Rakesh Parida 1 & Arindam Chakraborty 3 & Santanab Giri 1 Received: 24 May 2018 /Accepted: 21 August 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Alkali metal cations and halogen anions are common components of ionic salts. Recently, a new class of salts termed supersalts was reported, each of which contains a superalkali and a superhalogen that mimic an alkali metal cation and a halogen anion, respectively. Using three different functionals, namely B3LYP, wB97X, and M06-2X, we theoretically investigated a new subset of supersalts composed of Zintl-based superalkalis and inorganic superhalogens via computational modeling. The calculated dipole moment and first-order hyperpolarizability values for these supersalts indicate that they present nonlinear optical (NLO) behavior. The supersalts of Zintl superalkalis (Ca 2 P 7 , Sr 2 P 7 , Ba 2 P 7 ) and superhalogens (BF 4 , BeF 3 , NO 3 ) studied here were found to be stable. Keywords Zintl ion . Ionization energy . Superalkali . Electron affinity . Superhalogens . DFT . Supersalts Introduction Large ensembles of bound atoms known as atomic clusters are currently of great interest to experimentalists as well as theo- reticians. Such clusters represent a new phase of matter with properties that are governed by the size and composition of the cluster as well as the geometrical arrangement of the atoms within it [1]. The discovery of a new hypervalent atomic clus- ter with a lower ionization energy than that of an alkali metal was reported more than three decades ago by Gutsev and Boldyrev [2]. Boldyrev denoted atomic clusters of this type Bsuperalkalis,^ and proposed a general formula of XM n +1 for them, where M represents an alkali metal atom and X is an electronegative atom of valence n. In another work, Gutsev and Boldyrev [3] showed that atomic clusters of general for- mula MX k +1 (where M is a metal atom of valence k and X is a halogen atom) mimic halogen atoms and present much stron- ger electron affinities than halogens. These atomic clusters were subsequently termed Bsuperhalogens.^ The introduction of superalkalis and superhalogens opened up a new field of fundamental research in experimental and computational chemistry. Typical examples of superalkalis include FLi 2 , OLi 3 , and NLi 4 [4]. Experimental studies advocating the ex- istence of superalkalis [5–14] and superhalogens [15–18] have already been reported. While superalkalis exhibit strong re- ducing properties, superhalogens act as weakly coordinating strong oxidants. Superalkalis can be used to synthesize a va- riety of charge-transfer salts by coordinating them with spe- cies that have low electron affinities. Superalkalis and superhalogens have attracted considerable research interest over the past decade, and are now considered to be the basic building blocks for a new class of molecules, the supersalts [19–23]. Atomic and molecular clusters can be used to tailor materials with specific properties [24, 25], and superalkalis can be employed in a similar manner to produce tailored supersalts [26–29]. A recent work [30] reported the existence of a new class of superalkalis in which a Zintl ion [31–36] core is coordinated This paper belongs to Topical Collection International Conference on Systems and Processes in Physics, Chemistry and Biology (ICSPPCB- 2018) in honor of Professor Pratim K. Chattaraj on his sixtieth birthday Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00894-018-3806-5) contains supplementary material, which is available to authorized users. * Arindam Chakraborty ac201076@gmail.com * Santanab Giri giris@nitrkl.ac.in 1 Department of Chemistry, National Institute of Technology Rourkela, Odisha 769008, India 2 Department of Chemistry, Utkal University, Vani Vihar Bhubaneswar, Odisha 751004, India 3 Faculty of Science, Jatragachi Pranabananda High School, New Town, Kolkata 700161, India Journal of Molecular Modeling (2018) 24:306 https://doi.org/10.1007/s00894-018-3806-5